Int. No. 1490-B

By Council Member Sanchez (by request of the Mayor)

A Local Law to amend the administrative code of the city of New York, in relation to conforming the New York city energy conservation code to the New York state energy code with amendments unique to construction in the city, and to repeal section 28-1001.2 of such administrative code relating to such conforming amendments

Be it enacted by the Council as follows:

Section 1. Statement of findings and purpose. The New York State Energy Conservation Construction Code (the “New York State Energy Code”) is promulgated by the State Fire Prevention and Building Code Council pursuant to Article 11 of the New York State Energy Law. In accordance with Article 11, the New York City Energy Conservation Code is stricter than the New York State Energy Code. The purpose of this local law is to conform the New York City Energy Conservation Code to recent changes in the New York State Energy Code with local law amendments unique to construction in the city. 

§ 2. The definition of “NEW YORK STATE ENERGY CODE” in section 28-1001.1.1 of the administrative code of the city of New York, as amended by local law number 48 for the year 2020, is amended to read as follows:

NEW YORK STATE ENERGY CODE. The term “New York State Energy Code” means the  New York State Energy Conservation Construction Code, constituting part 1240 of title 19 of the New York codes, rules and regulations (19 NYCRR Part 1240), and the publications incorporated by reference in such part, promulgated on [February 12, 2020] October 1, 2025, by the State Fire Prevention and Building Code Council pursuant to Article 11 of the New York State Energy Law.

§ 3. Section 28-1001.2 of the administrative code of the city of New York is REPEALED and a new Section 28-1001.2 is added to read as follows:

§ 28-1001.2 New York city amendments to the New York state energy code. The following New York city amendments to the New York state energy code are hereby adopted as set forth in Sections 28-1001.2.1 and 28-1001.2.2.

§ 28-1001.2.1 New York city amendments to commercial and residential chapters of the New York state energy code.

Chapter 1 [CE] and Chapter 1 [RE]

Delete Chapter C1 and Chapter R1 in their entirety and replace with a new Chapter 1 to read as follows:

CHAPTER 1

ADMINISTRATION

INTRODUCTORY STATEMENT

The New York City Energy Conservation Code (“NYCECC”) is comprised of the publication entitled the 2025 Energy Conservation Construction Code of New York State (“ECCCNYS”) with amendments as enacted into law by the city. Reflecting these amendments to the ECCCNYS, the NYCECC is divided into provisions relevant to commercial buildings and provisions relevant to residential buildings as follows:

1.                     The provisions of the NYCECC for commercial buildings are reflected in the state publications incorporated by reference in 19 NYCRR Sections 1240.3 and 1240.5, as amended by Sections 28-1001.2.1 and 28-1001.2.2 of the Administrative Code. Such state publications include (i) Chapters 1 [CE], 2 [CE], 3 [CE], 4 [CE], 5 [CE] and 6 [CE] of ECCCNYS; (ii) the New York State-specific version of the publication entitled “Standard 90.1, Energy Standard for Buildings Except Low-Rise Residential Buildings,” published by the International Code Council, as incorporated in the ECCCNYS (“2025 NYS ASHRAE 90.1”); and (iii) reference standards incorporated by reference in subdivision (c) of 19 NYCRR Section 1240.3.

2.                     The provisions of the NYCECC for residential buildings are reflected in the state publications incorporated by reference in 19 NYCRR Section 1240.4, as amended by Sections 28-1001.2.1 of the Administrative Code. Such state publications include (i) Chapters 1 [RE], 2 [RE], 3 [RE], 4 [RE], 5 [RE] 6 [RE] and Appendix RF of the ECCCNYS; and (ii) the referenced standards incorporated by reference in subdivision (b) of 19 NYCRR Section 1240.4.

SECTION ECC 101

SCOPE AND GENERAL REQUIREMENTS

101.1 General. These provisions shall be known and cited as the “New York City Energy Conservation Code,” “NYCECC” or “ECC,” and are referred to herein as “this code.” All section numbers in this code shall be deemed to be preceded by the designation “ECC.” Administration and enforcement of this code shall be in accordance with Title 28 of the Administrative Code.

101.1.1 Titles.

The publication entitled 2025 Energy Conservation Construction Code of New York State shall be known as the “ECCCNYS.”

The New York State-specific version of the publication entitled “Standard 90.1, Energy Standard for Buildings Except Low-Rise Residential Buildings,” published by the International Code Council, as incorporated in the ECCCNYS shall be known as “2025 NYS ASHRAE 90.1.” All references in this code to “2025 NYC ASHRAE 90.1” reflect New York City amendments to 2025 NYS ASHRAE 90.1 as amended by Section 28-1001.2.2 of the Administrative Code.

The ECCCNYS, as contained in Part 1240 of Title 19 of the New York Codes, Rules and Regulations, along with the New York City amendments to such ECCCNYS shall be known collectively as the “New York City Energy Conservation Code” or “NYCECC.”

101.1.2 References. Where reference is made within this code to the Building Code of New York State, Existing Building Code of New York State, Fire Code of New York State, Fuel Gas Code of New York State, Mechanical Code of New York State, Plumbing Code of New York State, Property Maintenance Code of New York State, or Residential Code of New York State, the reference shall be deemed to be to the analogous provision of the New York City Construction Codes (Title 28 of the Administrative Code), the 1968 Building Code (Chapter 1 of Title 27 of the Administrative Code), the New York City Fire Code (Title 29 of the Administrative Code) or the New York City Electrical Code (Chapter 11 of Title 28 of the Administrative Code).

101.2 Scope. This code regulates the design and construction of commercial buildings and residential buildings, as defined in Chapter C2 and Chapter R2 of this code, accessory structures, building sites, and associated systems and equipment, as well as the repair, addition, alteration, or change of occupancy thereto for the use and conservation of energy and clean energy features, including the reduction in greenhouse gas emissions, over the life of each such commercial and residential building.

101.2.1 Statutory limitations. In the event of an addition to, or alteration of, an existing building or building system in an existing building that does not include a change of occupancy, nothing in the this code shall be interpreted to require any unaltered portion of such existing building or building system to comply with this code.

101.2.2 Occupancy classifications. For determination of occupancy classification and use within this code, a comparable occupancy classification shall be made to the New York City Building Code.

101.2.3 Reconciliation with New York State Energy Conservation Construction Code. Whenever any provision of the New York State Energy Conservation Construction Code provides for a more stringent requirement than imposed by this code, the more stringent requirement shall govern. The department may interpret provisions of this code that are (1) in addition to the provisions of the New York State Energy Conservation Construction Code or (2) more stringent than the provisions of such Code.

101.2.4 Other laws. The provisions of this code shall not be deemed to nullify any federal, state or local law, rule or regulation relating to any matter as to which this code does not provide, including but not limited to Articles 320 and 321 of Chapter 3 of Title 28 of the Administrative Code. Where the energy efficiency, energy use, or water use of covered products or equipment is subject to federal preemption pursuant to the Energy Policy and Conservation Act, the requirements set forth by the Department of Energy in the Code of Federal Regulations take precedence over any requirement in this Code.

101.2.5 Exceptions. This code shall not apply to the alterations of existing buildings set forth in items 1 through 7, provided that the alteration will not increase the energy usage of the building:

1. Storm windows installed over existing fenestration.

2. Glass-only replacements in an existing sash and frame, provided that the U-factor and the solar heat gain coefficient (SHGC) shall be equal to or lower than before the glass replacement.

3.                     Surface-applied window film installed on existing single-pane fenestration assemblies reducing solar heat gain, provided that this code does not require the glazing or fenestration to be replaced.

4. Reroofing where neither the sheathing nor the insulation is exposed. Roofs without insulation in the cavity and where the sheathing or insulation is exposed during reroofing shall be insulated either above or below the sheathing.

5. Replacement of existing doors that separate conditioned space from the exterior shall not require the installation of a vestibule or revolving door, provided that an existing vestibule that separates a conditioned space from the exterior shall not be removed.

6. An alteration that replaces less than 10 percent of the luminaires in a space, provided that such alteration does not increase the installed interior lighting power.

7. An alteration that replaces only the bulb and ballast within the existing luminaires in a space, provided that such alteration does not increase the installed interior lighting power.

101.3 Intent. This code shall regulate the design and construction of buildings for the use and conservation of energy over the life of each building. This code is intended to provide flexibility to permit the use of innovative approaches and techniques to achieve this objective. This code is not intended to abridge safety, health or environmental requirements contained in other applicable codes or ordinances. To the fullest extent feasible, use of modern technical methods, devices and improvements that tend to minimize consumption of energy without abridging reasonable requirements for the safety, health and security of the occupants or users of buildings shall be permitted. As far as may be practicable, the improvement of energy conservation construction practices, methods, equipment, materials and techniques shall be encouraged.

Nothing in this section or in any other provision of this code shall be construed to permit the commissioner to approve an application to waive, vary, modify or otherwise alter any provision of this code if such alteration would make such provision less restrictive than a standard or requirement of the ECCCNYS, unless the applicant has obtained approval for such alteration pursuant to Section 11-106 of the New York State Energy Law.

101.4 Applicability. The provisions of this code shall apply to the construction of buildings. Where, in any specific case, different sections of this code specify different materials, methods of construction or other requirements, the most restrictive provision shall govern. Where there is a conflict between a general requirement and a specific requirement, the specific requirement shall govern.

101.4.1 Mixed occupancy. Where a building, having not more than three stories above grade plane, includes both commercial and residential occupancies, each occupancy shall be separately considered and shall meet the applicable provisions of Chapters C2, C3, C4 and C5 for commercial or the applicable provisions of the 2025 NYC ASHRAE 90.1, and Chapters R2, R3, R4, and R5 for residential.

101.5 Compliance. Commercial buildings shall comply with the provisions of this code applicable to commercial buildings. Residential buildings shall comply with the provisions of this code applicable to residential buildings.

101.5.1 Compliance software. Where chosen by the applicant, compliance with the NYCECC-Commercial Provisions or Residential Provisions, or portion thereof, or, if applicable, with the 2025 NYC ASHRAE 90.1-can be demonstrated using either of the following:

1. Computer software that is developed by the United States Department of Energy (such as COMcheck©), specifically for the NYCECC or, if applicable, specifically for the 2025 NYC ASHRAE 90.1, or

2. Other software expressly approved in writing by the New York Secretary of State as acceptable for demonstrating compliance with the NYCECC or, if applicable, for demonstrating compliance with the 2025 NYC ASHRAE 90.1.

101.5.1.1 Other analysis tools. Other performance analysis tools used to document simulated building performance for a specified application or limited scope in accordance with Section C407 are subject to the approval of the building official.

101.5.1.2 Mandatory provisions. The use ofsoftware to demonstrate compliance with the commercial provisions, residential provisions, or 2025 NYC ASHRAE 90.1 as established by this code is not a defense to the failure to comply with any mandatory provision of this code. When using software to demonstrate compliance with the provisions of this code, compliance with all applicable mandatory provisions of this code is required.

101.5.2 Demonstration of compliance. For building project applications required to be submitted to the department, the following documentation, as further described in the rules of the department, shall be required in order to demonstrate compliance with this code:

101.5.2.1 Professional statement. Any registered design professional or lead energy professional filing an application or applications for a new building or alteration project shall provide on a signed and sealed drawing a statement of compliance or exemption in accordance with the rules of the department.

101.5.2.2 Energy analysis. For any application that is not exempt from this code and for which a work permit is required in accordance with Article 105 of Chapter 1 of Title 28 of the Administrative Code, an energy analysis shall be provided on a sheet or sheets within the construction drawing set. The energy analysis shall identify the compliance path followed, demonstrate how the design complies with this code and be in a format as prescribed in the rules of the department. The energy analysis shall meet the requirements of this code for the entire project. Projects that utilize trade-offs among disciplines shall use DOE2-based energy modeling programs or other energy-modeling programs as prescribed in the rules of the department and shall be signed and sealed by a lead energy professional.

101.5.2.3 Supporting documentation. For any application that is not exempt from this code and for which a work permit is required in accordance with Article 105 of Chapter 1 of Title 28 of the Administrative Code, supporting documentation shall be required in the approved construction drawings. See Section ECC 103 for further requirements.

SECTION ECC 102

ALTERNATIVE MATERIALS, METHODS OF CONSTRUCTION, DESIGNS OR INSULATING SYSTEMS

102.1 General. This code is not intended to prevent the use of any material, method of construction, design or insulating system not specifically prescribed herein, provided that such material, method of construction, design or insulating system has been approved by the commissioner as (1) meeting the intent of this code, (2) achieving energy savings that are equivalent to or greater than would be achieved using prescribed materials, methods of construction, designs or insulating systems, and (3) meeting the requirements of Article 113 of Chapter 1 of Title 28 of the Administrative Code and the New York City Construction Codes.

Nothing in this section shall be construed to permit the commissioner to approve an application that would waive, vary, modify, or otherwise alter any provision, standard, or requirement of this code if such alteration would make such provision less restrictive than a standard or requirement of the ECCCNYS unless the applicant has obtained approval for such alteration pursuant to Section 11-106 of the New York State Energy Law.

SECTION ECC 103

CONSTRUCTION DOCUMENTS

103.1 General. Construction documents shall be prepared in accordance with the provisions of Chapter 1 of Title 28 of the Administrative Code, the New York City Construction Codes, including this code, and the rules of the department.

103.2 Supporting documentation on construction documents. Supporting documentation shall include those construction documents that demonstrate compliance with this code.

103.2.1 Intent. Supporting documentation shall accomplish the following:

1. Demonstrate conformance of approved drawings to the energy analysis for every element and value of the energy analysis;

2. Demonstrate conformance of approved drawings to other mandatory requirements of this code, including, but not limited to, sealing against air leakage from the building envelope and from ductwork as applicable, insulation of ducts and piping as applicable, mechanical and lighting controls with devices shown and operational narratives for each, and additional requirements as set forth in this section;

3. Identify required progress inspections in accordance with the scope of work, this code, the Administrative Code, the New York City Building Code and the rules of the department; and

4. Comply with other requirements as may be set forth in the rules of the department.

103.2.2 Detailed requirements. Construction documents shall be drawn to scale upon suitable material. Electronic media documents are permitted to be submitted in accordance with department procedures. Construction documents for a project shall be fully coordinated and of sufficient clarity to indicate the location, nature and extent of the work proposed, and show in sufficient detail pertinent data and features of the building, building systems and equipment as herein governed. Details shall include, but are not limited to, as applicable, the following:

1. Energy Code compliance path.

2. Insulation materials and their R-values.

3. Fenestration U-factors and solar heat gain coefficients (SHGCs).

4. Area-weighted average U-factor and solar heat gain coefficient (SHGC) calculations.5. Air barrier and air sealing details, including the location of the air barrier.

6. Thermal bridges as identified in Section C402.7.

7. Mechanical system design criteria.

8. Mechanical and service water heating systems and equipment types, sizes and efficiencies.

9. Economizer description.

10. Equipment and system controls.

11. Fan motor horsepower (hp) and controls.

12. Duct sealing, duct and pipe insulation and location.

13. Lighting fixture schedule with wattage and control narrative.

14. Location of daylight zones on floor plans.

15. Location of pathways for routing of raceways or cable from the on-site renewable energy system to the electrical distribution equipment, where provided.

16. Location reserved for inverters, metering equipment and energy storage system (ESS), and a pathway reserved for routing of raceways or conduit from the on-site renewable energy system to the point of interconnection with the electrical service and the ESS, where provided.

17. Location and layout of a designated area for ESS, where provided.

18. Rated energy capacity and rated power capacity of the installed or planned ESS.

19. Location of designated EVSE spaces, EV ready spaces, and EV capable spaces in parking facilities and location of planned off-street loading spaces for future medium or heavy-duty EVSE.

20. Location of pathways for routing of raceways or cable from the enclosure or outlet of EV capable spaces to the electrical distribution equipment.

103.3 Examination of documents. In accordance with Article 104 of Chapter 1 of Title 28 of the Administrative Code, the department shall examine or cause to be examined the accompanying construction documents and shall ascertain by such examinations whether the construction indicated and described is in accordance with the requirements of this code and other pertinent laws, rules and regulations.

103.4 Changes during construction. For changes during construction refer to Section 28-104.3 of the Administrative Code.

SECTION ECC 104

INSPECTIONS

104.1 General. Except as otherwise specifically provided, inspections required by this code or by the department during the progress of work may be performed on behalf of the owner by an approved agency. All inspections shall be performed at the sole cost and expense of the owner. Refer to Article 116 of Chapter 1 of Title 28 of the Administrative Code for additional provisions relating to inspections. In addition to any inspections otherwise required by this code or the rules of the department, the following inspections shall be required: 

1. Progress inspections. Progress inspections shall be performed in accordance with the rules of the department.

2.                      Final inspection. Refer to Article 116 of Chapter 1 of Title 28 of the Administrative Code and the rules of the department.

3.                      Issuance of Certificate of Compliance. Refer to Section 28-116.4.1 of the Administrative Code. 

The requirements of this section shall not prohibit the operation of any heating equipment or appliances installed to replace existing heating equipment or appliances serving an occupied portion of a structure, provided that a request for inspection of such heating equipment or appliances has been filed with the department not more than 48 hours after such replacement work is completed, and before any portion of such equipment or appliances is concealed by any permanent portion of the structure. 

104.1.1 Approved agencies. Refer to Article 114 of Chapter 1 of Title 28 of the Administrative Code and the rules of the department.

104.1.2 Inspection of prefabricated construction assemblies. Prior to the issuance of a work permit for a prefabricated construction assembly having concealed mechanical work, the department shall require the submittal of an evaluation report by the manufacturer or approved agency on each prefabricated construction assembly, indicating the complete details of the mechanical system, including a description of the system and its components, the basis upon which the system is being evaluated for energy use, test results and similar information, and other data as necessary for the commissioner to determine conformance to this code.

104.1.2.1                     Test and inspection records. Required test and inspection records shall be made available to the commissioner at all times during the fabrication of the mechanical system and the erection of the building; or such records as the commissioner designates shall be filed.

104.2 Testing. Envelope, heating, ventilating, air conditioning, service water heating, lighting and electrical systems shall be tested as required in this code and in accordance with Sections 104.2.1 through 104.2.3. Except as otherwise required in this code or in the rules of the department, tests shall be made by the permit holder and witnessed by an approved agency.

104.2.1 New, altered, extended, renovated or repaired systems. New envelope, heating, ventilating, air conditioning, service water heating, lighting and electrical installations or systems, and parts of existing systems that have been altered, extended, renovated or repaired, shall be tested as prescribed herein or in the rules of the department to disclose leaks and defects.

104.2.2 Apparatus, instruments, material and labor for tests. Apparatus, instruments, material and labor required for testing an envelope, heating, ventilating, air conditioning, service water heating, lighting or electrical installation or system, or part thereof, shall be furnished by the permit holder.

104.2.3 Reinspection and testing. Where any work or installation does not pass an initial test or inspection, the necessary corrections shall be made so as to achieve compliance with the New York City Construction Codes, including this code. The work or installation shall then be reinspected or retested by the approved agency.

104.3 Sign-off of completed work. In addition to the requirements of Article 116 of Chapter 1 of Title 28 of the Administrative Code, Section 103.4 of this code, and other requirements for sign-off, the project team shall either certify that construction does not differ from the last approved energy analysis or provide a whole-project as-built energy analysis and supporting documents, signed and sealed, for approval prior to sign-off. The as-built energy analysis and supporting documents shall reflect the materials, equipment and values actually used in the construction of the project, and shall demonstrate compliance of the constructed project with this code. Such signed and sealed documents may be accepted with less than full examination by the department based on the professional certification of the registered design professional.

104.4 Temporary connection. The commissioner shall have the authority to allow the temporary connection of an installation to the sources of energy for the purpose of testing the installation or for use under a temporary certificate of occupancy.

SECTION ECC 105

REFERENCED STANDARDS

105.1 Referenced standards. The standards referenced in Chapters C2, C3, C4, and C5 of this code shall be those that are listed in Chapter C6 of this code, and in the rules of the department and such standards shall be considered part of the requirements of the commercial provisions of this code to the prescribed extent of each such reference. The standards referenced in Chapters R2, R3, R4, and R5, of this code shall be those that are listed in Chapter R6 of this code, and in the rules of the department and such standards shall be considered part of the requirements of the residential provisions of this code to the prescribed extent of each such reference. The standards referenced in 2025 NYC ASHRAE 90.1 of this code shall be those that are listed in Section 12 of 2025 NYC ASHRAE 90.1 of this code, and in the rules of the department and such standards shall be considered part of the requirements of the commercial provisions of this code to the prescribed extent of each such reference. Where differences occur between provisions of this code and the referenced standards, the provisions of this code shall apply. Refer to Article 103 of Chapter 1 of Title 28 of the Administrative Code for additional provisions relating to referenced standards.

CHAPTER C2

DEFINITIONS

SECTION C201

GENERAL

Section C201.3 Words and terms defined in other codes.

Section C201.3 - Revise Section C201.3 to read as follows:

C201.3 Words and terms defined in other codes. Where italicized words and terms are not defined in this code but are defined in the New York City Building Code, New York City Fire Code, New York City Fuel Gas Code, New York City Mechanical Code, and New York City Plumbing Code, such terms shall have the meanings ascribed to them in those codes.

Section C201.4 Words and terms not defined.

Section C201.4 - Revise Section C201.4 to read as follows:

C201.4 Words and terms not defined. Where words and terms are not italicized or are italicized but not defined in this publication or in the publications listed in Section C201.3, such words and terms shall have the meanings defined in applicable referenced standards, statutes, or regulations or shall have the ordinarily accepted meanings such as the context implies.

Section C202

GENERAL DEFINITIONS

Section C202 - Delete the definitions of “Building Code of New York State,” “Existing Building Code of New York State,” “Fire Code of New York State,” “Fuel Gas Code of New York State,” “Mechanical Code of New York State,” “Plumbing Code of New York State,” ”Property Maintenance Code of New York State,” “Residential Code of New York State,” and “Uniform Code.”

Section C202 - Add the definition of “2025 NYC ASHRAE 90.1” after the definition of “2025 NYS ASHRAE 90.1.” to read as follows:

2025 NYC ASHRAE 90.1. New York City amendments to 2025 NYS ASHRAE 90.1 

Section C202 - Delete the definition of “Approval Or Approved,” “Approved Agency,”  after the definition of “Alteration.”

Section C202 - Add the definition of “Approval Or Approved,” “Approved Agency,” after the definition of “Alteration,” to read as follows:

APPROVAL OR APPROVED. See Section 28-101.5 of the Administrative Code.

APPROVED AGENCY. See Section 28-101.5 of the Administrative Code.

Section C202 - Delete the definition of “Authority Having Jurisdiction,” after the definition of “Area-Weighted Average.”

Section C202 - Add the definition of “Authority Having Jurisdiction,” after the definition of “Area-Weighted Average,” to read as follows:

AUTHORITY HAVING JURISDICTION. The governmental unit or agency responsible for administration and enforcement of the New York City Construction Codes and NYCECC.

Section C202 - Delete the definition of “Basement,” after the definition of “Automatic.”

Section C202 - Add the definition of “Basement Or Cellar, Energy Code,” after the definition of “”Automatic””,” to read as follows:

BASEMENT OR CELLAR, ENERGY CODE. A story that is not a story above grade plane. See “Story above grade plane.”

Section C202 - Delete the definition of “Building Entrance,” “Building Official,” after the definition of “Building Commissioning.”

Section C202 - Add the definition of “Building Entrance,” “Building Official” after the definition of “Building Commissioning,” to read as follows:

BUILDING ENTRANCE. Any doorway, set of doors, revolving door, vestibule, or other form of portal that is ordinarily used to gain access to the building or to exit from the building by its users and occupants. This does not include doors solely used to directly enter mechanical, electrical, or other building utility service equipment rooms.

BUILDING OFFICIAL. The commissioner of buildings of the City of New York or his or her duly authorized representative. See Section 28-101.5 of the Administrative Code.

Section C202 - Delete the definition of “Building Thermal Envelope,” after the definition of “Building System.”

Section C202 - Add the definition of “Building Thermal Envelope,” after the definition of “Building System,” to read as follows:

BUILDING THERMAL ENVELOPE. The exterior walls, floors, slabs, ceilings, roofs, fenestration, and any other building element assemblies (above and below grade) that enclose conditioned space or provide a boundary between conditioned space and unconditioned space.

Section C202 - Delete the definition of “Chi-Factor (Χ-Factor),” after the definition of “Character-Defining Features.”

Section C202 - Add the definition of “Chi-Factor (Χ-Factor),”  after the definition of  “Character-Defining Features,” to read as follows:

CHI-FACTOR (χ-FACTOR). See “Thermal Bridge.”

Section C202 - Add the definition of “Clear Field Thermal Bridge,” “Clear Field U-Factor,”       after the definition of “Clean Water Pump,” to read as follows:

CLEAR FIELD THERMAL BRIDGE. See “Thermal Bridge.”

CLEAR FIELD U-FACTOR. See “Thermal Bridge.”

Section C202 - Add the definition of “Commissioner,” “Commissioning Plan,” after the definition of “Commercial Building,” to read as follows:

COMMISSIONER. The commissioner of buildings of the city of New York, or his or her duly authorized representative. See “Authority Having Jurisdiction” and “Building official”.

COMMISSIONING PLAN. See Section C408.2.1, Commissioning plan.

Section C202 - Delete the definition of “Energy Code,” after the definition of “Energy Analysis.”

Section C202 - Add the definition of “Energy Code,” after the definition of “Energy Analysis,” to read as follows:

ENERGY CODE. The New York City Energy Conservation Code.

Section C202 - Delete the definition of “Fenestration,” after the definition of “Fault Detection and Diagnostics (FDD) System.”

Section C202 - Add the definition of “Fenestration,” after the definition of “Fault Detection and Diagnostics (FDD) System,” to read as follows:

FENESTRATION. Products classified as either skylights or vertical fenestration.

Skylights. Glass units or other transparent or translucent glazing material installed at a slope of less than 60 degrees (1.05 rad) from horizontal, including unit skylights, tubular daylighting devices and glazing materials in solariums, sunrooms, roofs, greenhouses and sloped walls. A skylight includes the glazing assembly plus perimeter framing components.

Vertical fenestration. Window units that are fixed or operable, doors that are more than half glazed, glazed block, and combination opaque and glazed doors composed of glass or other transparent or translucent glazing materials, and installed at a slope of not less than 60 degrees (1.05 rad) from horizontal.

Section C202 - Add the definition of “Grade, Energy Finished,” “Grade Plane, Energy,” after the definition of “General Lighting,” to read as follows:

GRADE, ENERGY FINISHED. The final top surface of lawns, walks, driveways, areaways, or other non-vertical surfaces where the surface meets the foundation, slab edge or exterior wall of a building.

GRADE PLANE, ENERGY. A reference plane representing the average of finished ground level adjoining the building at exterior walls. Where the finished ground level slopes away from the exterior walls, the reference plane shall be established by the lowest points within the area between the building and the lot line or, where the lot line is more than 6 feet (1828.8 mm) from the building, between the building and a point 6 feet (1828.8 mm) from the building.

Section C202 - Delete the definition of “HVAC Total System Performance Ratio (HVAC TSPR),” after the definition of “Humidistatic Controls.”

Section C202 - Add the definition of “HVAC Total System Performance Ratio (HVAC TSPR),”    after the definition of “Humidistatic Controls,” to read as follows:

HVAC TOTAL SYSTEM PERFORMANCE RATIO (HVAC TSPR). The ratio of the sum of a building’s annual heating and cooling load in thousands of Btus to the sum of annual site energy consumption of the building HVAC systems in thousands of Btu.

Section C202 - Add the definition of “Integrated Seasonal Coefficient Of Performance (ISCOP),” “Integrated Seasonal Moisture Removal Efficiency (ISMRE),” after the definition of “Integrated Part Load Value (IPLV),” to read as follows:

INTEGRATED SEASONAL COEFFICIENT OF PERFORMANCE (ISCOP). A seasonal efficiency number that is a combined value based on the formula listed in AHRI Standard 920 of the 2 COP values for the heating season of a DX-DOAS unit water or air source heat pump, expressed in W/W.

INTEGRATED SEASONAL MOISTURE REMOVAL EFFICIENCY (ISMRE). A seasonal efficiency number that is a combined value based on the formula listed in AHRI Standard 920 of the 4 dehumidification moisture removal efficiency (MRE) ratings required for DX-DOAS units, expressed in lb of moisture/kWh.

Section C202 - Delete the definition of “Labeled” after the definition of “Isolation Devices.”

Section C202 - Add the definition of “Labeled,” after the definition of “Isolation Devices” to read as follows:

LABELED. See Section 28-101.5 of the Administrative Code.

Section C202 - Add the definition of “Lead Energy Professional,” after the definition of “Large-Diameter Ceiling Fan,” to read as follows:

LEAD ENERGY PROFESSIONAL. The registered design professional who signs and seals the energy analysis for an entire project. Such individual may be the same registered design professional who signs and seals the design drawings for the same project.

Section C202 - Add the definition of “Linear Thermal Bridge,” after the definition of “Liquid Fuel,” to read as follows:

LINEAR THERMAL BRIDGE. See “Thermal Bridge.”

Section C202 - Delete the definition of “Listed” after the definition of “Liner System (Ls).”

Section C202 - Add the definition of “Listed,” after the definition of “Liner System (Ls),” to read as follows:

LISTED. See Section 28-101.5 of the Administrative Code. 

Section C202 - Delete the definition of “Market Value” after the definition of “Manual.”

Section C202 - Add the definition of “Moisture Removal Efficiency (MRE),” after the definition of “Manual,” to read as follows:

MOISTURE REMOVAL EFFICIENCY (MRE). A ratio of the moisture removal capacity in pounds of moisture per hour to the power input values in kilowatts at any given set of standard rating conditions expressed in lb of moisture/kWh.

Section C202 - Add the definitions of “Point Thermal Bridge,” after the definition of “Physical Renewable Energy Power Purchase Agreement,” to read as follows:

POINT THERMAL BRIDGE. See “Thermal Bridge.”

Section C202 - Add the definitions of “Pre-Engineered Metal Building,” “Professional Certification,” “Project,” after the definition of “Process Application,” to read as follows:

PRE-ENGINEERED METAL BUILDING. A structure in which the steel components-primary framing, secondary framing, and cladding-are designed and manufactured in a factory according to specific project requirements and then shipped to the construction site for assembly.

PROFESSIONAL CERTIFICATION. See Section 28-101.5 of the Administrative Code.

PROJECT. A design and construction undertaking comprised of work related to one or more buildings and the site improvements. A project is represented by one or more work applications, including construction documents compiled in accordance with Section 107 of the New York City Building Code, that relate either to the construction of a new building or buildings or to the demolition or alteration of an existing building or buildings. Applications for a project may have different registered design professionals and different job numbers, and may result in the issuance of one or more permits.

Section C202 - Delete the definition of “PSI-FACTOR (ψ-FACTOR)” after the definition of “Proposed Design.”

Section C202 - Add the definition of “PSI-FACTOR (ψ-FACTOR),” after the definition of “Proposed Design,” to read as follows:

PSI-FACTOR (ψ-FACTOR). See “Thermal Bridge.”

Section C202 - Delete the definitions of “Standard Reference Design” after the definition of “Solar Heat Gain Coefficient (SHGC).”

Section C202 - Add the definition of “Spandrel Panel,” after the definition of “Solar Heat Gain Coefficient (SHGC),” to read as follows:

SPANDREL PANEL. An opaque assembly within a fenestration framing system in a wall that is part of the building thermal envelope. Such panels are considered to be a portion of the opaque thermal envelope assembly.

Section C202 - Add the definitions of “Story,” “Story Above Grade Plane,” after the definition of “Storefront,” to read as follows:

STORY. The portion of a building included between the upper surface of a floor and the upper surface of the floor or roof next above. See the definitions of “Basement or Cellar, Energy Code,” and “Grade Plane, Energy Code.” A story is measured as the vertical distance from top to top of two successive tiers of beams or finished floor surfaces and, for the topmost story, from the top of the floor finish to the top of the ceiling joists or, where there is not a ceiling, to the top of the roof rafters. 

STORY ABOVE GRADE PLANE. Any story having its finished floor surface entirely above grade plane, or in which the finished surface of the floor next above is:

1. More than 6 feet (1828.8 mm) above average grade plane; or

2. More than 12 feet (3657.6 mm) above the finished ground level at any point.

Section C202 - Delete the definition of “Thermal Bridge” after the definition of “Thermal Block.”

Section C202 - Add the definitions of “Thermal Break Device,” “Thermal Bridge,” after the definition of “Thermal Block,” to read as follows:

THERMAL BREAK DEVICE. A pre-manufactured, load-bearing building component composed of multiple materials of differing thermal conductivities (e.g., steel, insulation, fiber-reinforced polymers) designed to structurally connect building elements while reducing thermal bridging. The thermal transmittance (U-value) or equivalent thermal conductivity (λeq) of such elements shall be determined using physical testing in accordance with ASTM C1363 or an approved equivalent calculation method. The calculated performance (U-value or equivalent thermal conductivity) shall include the effects of all embedded components through psi- or chi-value calculation methods.

THERMAL BRIDGE. An element or interface of elements that has higher thermal conductivity than the surrounding building thermal envelope, which creates a path of least resistance for heat transfer.

CHI-FACTOR (χ-FACTOR). The heat loss factor for a single thermal bridge characterized as a point element of a building thermal envelope (Btu/h x °F) [W/K].

CLEAR FIELD THERMAL BRIDGE. Elements of a building envelope assembly creating paths of decreased resistance for heat transfer which repeat at regular intervals, such as metal or wood studs, girts, and purlins.

CLEAR FIELD U-FACTOR. Thermal performance factor that accounts for clear field thermal bridge.

LINEAR THERMAL BRIDGE. a length-based element associated with horizontal, vertical, or diagonal elements that penetrates the insulation in the building thermal envelope and with a length measured along an exterior surface of the building thermal envelope, such as balconies, parapet-, roof-, floor-, or fenestration intersections, and shelf angles.

POINT THERMAL BRIDGE. An element that penetrates the insulation in the building thermal envelope, such as columns or beams passing through envelope assemblies, attachments, anchors, and connections not defined as clear field- or linear thermal bridges. The cross-sectional area is measured at the external surface of the outermost penetrated insulation layer.

PSI-FACTOR (ψ-FACTOR). The heat loss factor per unit length of a thermal bridge characterized as a linear element of a building thermal envelope (Btu/h x ft x °F) [W/(m x K)].

Section C202 - Delete the definitions of “Wall, Above-Grade,” “Wall, Below-Grade,” after the definition of “Walk-In Freezer.”

Section C202 - Add the definitions of “Wall, Above-Grade,” “Wall, Below-Grade,” after the definition of “Walk-In Freezer,” to read as follows:

WALL, ABOVE-GRADE. A wall associated with the building thermal envelope that is more than 15 percent of the total surface area above adjoining grade plane and is on the exterior of the building or any wall that is associated with the building thermal envelope that is not on the exterior of the building. This includes, but is not limited to, areaways below grade, between-floor spandrels, peripheral edges of floors, roof knee walls, dormer walls, gable end walls, walls enclosing a mansard roof, mechanical equipment penetrations, and skylight shafts.

WALL, BELOW-GRADE. A wall associated with the basement or first story of the building that is part of the building thermal envelope, has not less than 85 percent of the total surface area below adjoining grade, and is on the exterior of the building.

CHAPTER C3

GENERAL REQUIREMENTS

SECTION ECC C301

CLIMATE ZONES

Section C301.1 General.

Section C301.1 - Revise Section C301.1 to read as follows:

C301.1 General. For projects in the city of New York, Climate Zone 4A shall be used in determining the applicable requirements from Chapter C4.

SECTION C303

MATERIALS, SYSTEMS AND EQUIPMENT

Section C303.1.1 Building thermal envelope insulation.

Section C303.1.1 - Revise the Exception to Section C303.1.1 to read as follows:

Exception: For roof insulation installed above the deck, the R-value shall be labeled as required by the material standards in New York City Building Code.

Section C303.1.2 Insulation mark installation.

Section C303.1.2 - Revise the Exception to Section C303.12 to read as follows:

Exception: For roof insulation installed above the deck, the R-value shall be labeled as specified by the material standards in New York City Building Code.

Section C303.1.3 Fenestration product rating.

Section C303.1.3 - Revise Section C303.1.3 to read as follows:

C303.1.3 Fenestration product rating. Fenestration product rating. U-factors, solar heat gain coefficient (SHGC), and visible transmittance (VT) of fenestration products shall be determined as follows:

1. For windows, doors and skylights, U-factor, SHGC and VT ratings shall be determined by a third party recognized by ANSI, ILAC or MiRa in accordance with NFRC 100 and NFRC 200.

2. Where required for garage doors and rolling doors, U-factor ratings shall be determined in accordance with either NFRC 100 or ANSI/DASMA 105.

U-factors, SHGC and VT shall be determined by an accredited, independent laboratory, and certified by the manufacturer by a label affixed to the product or a label certificate specific to the products in the project.

Manufactured products or shop fabricated units lacking an affixed label shall be assigned a default U-factor from Table C303.1.3(1) or C303.1.3(2). Products lacking a label indicating SHGC or VT shall be assigned a default SHGC or VT from Table C303.1.3(3).

Where labeled or default values are not indicated, a signed and dated certificate showing compliance through modeling performed using Lawrence Berkley National Labs WINDOW/THERM software at the sizes and boundary conditions prescribed in NFRC -100/200 shall be provided. The simulation shall be performed by a third-party recognized by ANSI, ILAC or MiRa. For Tubular Daylighting Devices, VTannual shall be measured and rated in accordance with NFRC 203.

Air infiltration rate shall be demonstrated by testing to ASTM E283. The test shall be conducted at an independent third-party laboratory recognized by ANSI, ILAC or MiRa, and shall be conducted within the previous 5 years.    

Section C303.1.5 Spandrel Panels.

Section C303.1.5 - Add new Section C303.1.5 and Table C303.1.5 to read as follows:

C303.1.5 Spandrel Panels. U-factors of opaque assemblies within fenestration framing systems shall be determined in accordance with NFRC 100. U-factors shall be determined by an accredited, independent laboratory. Spandrel panels lacking a calculation shall be assigned a default U-factor from Table C303.1.5.

TABLE C303.1.5

DEFAULT EFFECTIVE U-FACTORS FOR SPANDREL PANELS^a

a .Extrapolation outside of the table and interpolation between values in the table shall not be permitted. Assemblies with distance between framing less than 30 inches (762 mm), or not included in the default table, shall have a U-factor determined by testing in compliance with ASTM C1363 or modeling in compliance with ANSI/NFRC 100. Spandrel panel assemblies in the table do not include metal backpans. For designs with metal backpans, multiply the U-factor by 1.20. U-factors for spandrel panels include a 3/4 in. air gap and 5/8 in. gypsum board with R-value of 0.56 for the interior finish. The gypsum board is assumed to span between the window sill and a channel at the floor.

b. This frame type shall be used for systems that do not contain a non-metallic element that separates the metal exposed to the exterior from the metal that is exposed to the interior condition.

c. This frame type shall be used for systems where a urethane or other non-metallic element separates the metal exposed to the exterior from the metal that is exposed to the interior condition.

d. This frame type shall be used for systems that have no exposed mullion on the exterior.

e. This frame type shall be used for systems where there is no framing, or the insulation is continuous across and uninterrupted by the framing (also known as mullion wrap).

Section C303.2 Installation.

Section C303.2 - Revise Section C303.2 to read as follows:

C303.2 Installation. Materials, systems and equipment shall be installed in accordance with (i) the manufacturer’s instructions and (ii) the applicable provisions of the New York City Construction Codes.

CHAPTER C4

COMMERCIAL ENERGY EFFICIENCY

SECTION C401

GENERAL

Section C401.2.1 ECCCNYS - Commercial Provisions.

Section C401.2.1 - Delete Section C401.2.1 in its entirety and add a new Section C401.2.1 to read as follows:

C401.2.1 New York City Energy Conservation Code. Commercial Provisions. Commercial buildings shall comply with Sections C402 through C406 and Section C408. Dwelling units and sleeping units in Group R-2 buildings without systems serving multiple units shall be deemed to be in compliance with this chapter, provided that they comply with Section R406 .

Exception: Additions, alterations, repairs and changes of occupancy to existing buildings that comply with Chapter C5.

Section C401.2.2 ASHRAE 90.1.

Section C401.2.2 - Delete Section C401.2.2 in its entirety and add a new Section C401.2.2 to read as follows:

C401.2.2 ASHRAE 90.1 Compliance Path. Commercial buildings shall comply with the requirements of 2025 NYC ASHRAE 90.1.

SECTION C402

BUILDING THERMAL ENVELOPE REQUIREMENTS

Table C402.1.2 Opaque Building Thermal Envelope Assembly Maximum Requirements, U-Factor Method^{a, b}

Revise Table C402.1.2 to read as follows:

TABLE C402.1.2

OPAQUE BUILDING THERMAL ENVELOPE ASSEMBLY MAXIMUM REQUIREMENTS, U-FACTOR METHOD^{a, b}

For SI: 1 pound per square foot = 4.88 kg/m2, 1 pound per cubic foot = 16 kg/m3.

a.                     Where assembly U-factors, C-factors and F-factors are established in 2025 NYC ASHRAE 90.1, such opaque assemblies shall be a compliance alternative where those values meet the criteria of this table, provided that the construction, excluding the cladding system on walls, complies with the appropriate construction details from 2025 NYC ASHRAE 90.1. 

b.                     Where U-factors have been established by testing in accordance with ASTM C1363, such opaque assemblies shall be a compliance alternative where those values meet the criteria of this table. The R-value of continuous insulation shall be permitted to be added to or subtracted from the original tested design. 

c.                     Where heated slabs are below grade, below-grade walls shall comply with the U-factor requirements for above-grade mass walls.

d.                     “Mass floors” shall be in accordance with Section C402.1.3.4.

e.                     Reserved. 

f.                     “Mass walls” shall be in accordance with Section C402.1.3.4.

g.                     Swinging door U-factors shall be determined in accordance with NFRC-100.

h.                     Garage doors having a single row of fenestration shall have an assembly U-factor less than or equal to 0.44, provided that the fenestration area is not less than 14 percent and not more than 25 percent of the total door area.

i.                     This refers to cold-formed steel studs or joists at 16” or 24” on-center. 

Section C402.1.2.1 Methods of determining U-, C- and F-factors.

Section C402.1.2.1 - Revise Section C402.1.2.1 to read as follows:

C402.1.2.1 Methods of determining U-, C- and F-factors. Where assembly U-factors , C-factors and F-factors and calculation procedures are established in 2025 NYC ASHRAE 90.1 Appendix A for opaque assemblies, such opaque assemblies shall be a compliance alternative provided they meet the criteria of Table C402.1.2 and the construction, excluding cladding system on walls, complies with the applicable construction details from 2025 NYC ASHRAE 90.1 Appendix A.  Where U-factors have been established by testing in accordance with ASTM C1363, such opaque assemblies shall be a compliance alternative provided they meet the criteria of Table C402.1.4. The R-value of continuous insulation shall be permitted to be added to or subtracted from the original tested design. Airspaces used for assembly evaluations shall comply with Section C402.2.7.

Section C402.1.2.1.6 Cold-formed steel assemblies.

Section C402.1.2.1.6 - Revise Section C402.1.2.1.6 to read as follows:

C402.1.2.1.6 Cold-formed steel assemblies. U-factors for building thermal envelopes containing cold-formed steel framed ceiling and walls shall be permitted to be determined in accordance with Table A3.3.3.1 in 2025 NYC ASHRAE 90.1. Where the steel-framed wall contains no cavity insulation and uses continuous insulation to satisfy the U-factor maximum, the steel-framed wall member spacing is permitted to be installed at any on-center spacing.

Section C402.1.2.1.7 Spandrel Panels.

Section C402.1.2.1.7 - Revise Section C402.1.2.1.7 to read as follows:

C402.1.2.1.7 Spandrel Panels. U-factors of opaque assemblies within fenestration framing systems shall be determined in accordance with ASTM C1363, ANSI/NFRC 100, or the default values in Table C303.1.5. 

Table C402.1.2.1.7 Effective U-Factors For Spandrel Panels.^a

Table C402.1.2.1.7 - Delete Table C402.1.2.1.7 in its entirety.

Table C402.1.3 Opaque Building Thermal Envelope Insulation Component Minimum Requirements, R-Value Method.^a

Revise Table C402.1.3 to read as follows:

TABLE C402.1.3

OPAQUE BUILDING THERMAL ENVELOPE INSULATION COMPONENT MINIMUM REQUIREMENTS, R-VALUE METHOD^a

For SI: 1 inch = 25.4 mm, 1 pound per square foot = 4.9 kg/m², 1 pound per cubic foot = 16 kg/m³.

ci = Continuous Insulation, NR = No Requirement, LS = Liner System, ca = Cavity insulation.

a.                     Assembly descriptions can be found 2025 NYC ASHRAE 90.1 Appendix A.

b.                     Where using R-value compliance method, a thermal spacer block shall be provided, otherwise use the U-factor compliance method in Table C402.1.2.

c.                      Reserved.

d.                     Where heated slabs are below grade, below-grade walls shall comply with the exterior insulation requirements for heated slabs.

e.                     “Mass floors” shall be in accordance with Section C402.1.3.4.

f.                     “Mass walls” shall be in accordance with Section C402.1.3.4.

g.                     The first value is for perimeter insulation and the second value is for full, under-slab insulation. Perimeter and full-slab insulation components shall be installed in accordance with Section C402.2.4.

h.  The first value is cavity insulation; the second value is continuous insulation. Therefore; “R-13ca+R-8.5ci” means R-13 cavity insulation and R-8.5 continuous insulation; “R-53ca” means R-53 cavity insulation and no continuous insulation.

i.  Where the required R-value in Table C402.1.3 is met by using continuous insulation such that cavity insulation is not required, the R-Value is applicable to any wall framing spacing.

j. This refers to cold-formed steel studs or joists at 16” or 24” on-center.

Section C402.1.5 Rooms containing fuel-burning appliances.

Section C402.1.5 - Revise the exception to Section C402.1.5 to read as follows:

Exception: Fireplaces and stoves that comply with the New York City Mechanical Code, and the fireplace blocking requirements of the New York City Building Code.

Section C402.2.7 Airspaces. 

Section C402.2.7 - Revise Section C402.2.7 to read as follows:

C402.2.7 Airspaces. Where the R-value of an airspace is used for compliance in accordance with Section C402.1, the airspace shall be enclosed in a cavity bounded on all sides by building components and constructed to minimize airflow into and out of the enclosed airspace. Airflow shall be deemed minimized where one of the following conditions occur:

1. The enclosed airspace is unventilated.

2. The enclosed airspace is bounded on at least one side by an anchored masonry veneer, constructed in accordance with Chapter 14 of the New York City Building Code and vented by veneer weep holes located only at the bottom of the airspace and spaced not less than 15 inches (381 mm) on center with top of the cavity airspace closed.

Exception: For ventilated cavities, the effect of ventilation of airspaces located on the exterior side of the continuous air barrier and adjacent to and behind the exterior wall-covering material shall be determined in accordance with ASTM C1363 modified with an airflow entering the bottom and exiting the top of the airspace at an air movement rate of not less than 70 mm/second.

Section C402.2.8 Fireplaces. 

Section C402.2.8 - Revise Section C402.2.8 to read as follows:

C402.2.8 Fireplaces. New wood-burning fireplaces shall have tight-fitting flue dampers or doors, and outdoor combustion air as required by the fireplace construction provisions of the New York City Construction Codes, as applicable. Where using tight-fitting doors on factory-built fireplaces listed and labeled in accordance with UL 127, the doors shall be tested and listed for the fireplace.

Table C402.5 Building Envelope Fenestration Maximum U-Factor And SHGC Requirements

Revise Table C402.5 to read as follows:

TABLE C402.5

BUILDING ENVELOPE FENESTRATION MAXIMUM U-FACTOR

AND SHGC REQUIREMENTS^c

a.                     U-factor shall be rated in accordance with NFRC 100. U-factor shall reflect project-specific sizes, and include framing components plus glazing. SHGC shall be rated in accordance with NRFC 200.

b.                     SHGC shall reflect project-specific sizes, and include framing components plus glazing. SHGC of the center-of-glass shall be an acceptable alternative for determining compliance with the SHGC requirements for the overall fenestration area.

c.                     Fixed fenestration shall include glazed curtain walls, pre-fabricated storefronts and factory assembled fixed window units.

d.                     Where a portion of the fenestration frame is installed at or above 95 feet (29 m) above grade, the unit may meet the requirements for 95 feet (29 m) and above.

Section C402.5.2 Minimum skylight fenestration area. 

Section C402.5.2 - Revise the first paragraph of Section C402.5.2 to read as follows:

C402.5.2 Minimum skylight fenestration area. Skylights shall be provided in enclosed spaces greater than 2500 square feet (232.3 m²) in floor area, directly under a roof with not less than 75 percent of the ceiling area with a ceiling height greater than 15 feet (4572 mm), and used as an office, lobby, atrium, concourse, corridor, storage space, gymnasium/exercise center, convention center, automotive service area, space where manufacturing occurs, nonrefrigerated warehouse, retail store, distribution/sorting area, transportation depot, parking garage, or workshop. The total toplit daylight zone shall be not less than half the floor area and shall comply with one of the following:

Section C402.5.3.4 Area-weighted U-factor. 

Section C402.5.3.4 - Revise Section C402.5.3.4 to read as follows:

C402.5.3.4 Area-weighted U-factor. An area-weighted average combining vertical fixed fenestration and vertical operable fenestration in accordance with Equation 4-4a shall be permitted to demonstrate compliance with the U-factor requirements for those categories in Table C402.5. Entrance door and skylight U-factors shall be permitted to be averaged separately by fenestration product category. All U-factors shall be rated in accordance with NFRC 100.

∑[(U1 * A1) … (Un * An)] ≤ (U_fixed * A_fixed + U_operable * A_operable)                       (Equation 4-4a)

where:

U1 = rated U-factor of the 1st vertical fenestration assembly

A1 = area of the 1st vertical fenestration assembly

Un = rated U-factor of the nth vertical fenestration assembly

An = area of the nth vertical fenestration assembly

U_fixed = U-factor for vertical fixed fenestration in Table C402.4 

A_fixed = total area of the vertical fixed fenestration assemblies

U_operable = U-factor for vertical operable fenestration in Table C402.4 

 A_operable = total area of the vertical operable fenestration assemblies.

Section C402.6.2 Air leakage compliance. 

Section C402.6.2. Delete Section C402.6.2, Section C402.6.2.1, Section C402.6.2.2,Section C402.6.2.3, Section C402.6.2.3.1 and Section C402.6.2.3.2 in their entirety and add new Section C402.6.2, Section C402.6.2.1, Section C402.6.2.2, Section C402.6.2.2.1 and Section C402.6.2.2.2 to read as follows:

C402.6.2 Air leakage compliance. Air leakage of the building thermal envelope shall be tested by an approved third party in accordance with Section C402.6.2.1 and C402.6.2.2. The measured air leakage shall not be greater than 0.35 cubic feet per minute per square foot (1.8 L/s/m2) of the building thermal envelope area at a pressure differential of 0.3 inch (7.6 mm) water gauge (75 Pa) with the calculated building thermal envelope surface area being the sum of the above- and below-grade building thermal envelope.

C402.6.2.1 Whole building test method and reporting. The whole building thermal envelope shall be tested by an approved third party in accordance with ASTM E779, ASTM E1827, ASTM E3158 or an equivalent approved method. Air leakage shall be measured following a multi-point regression method and then averaged from depressurization and pressurization tests. A report that includes the tested surface area, floor area, air by volume, stories above grade, and air leakage rates shall be submitted to the building official and the building owner

Exceptions:

 1.                     For buildings greater than 50 000 square feet (4645.2 m²), portions of the building shall be permitted to be tested following the procedures for a guarded test in ASTM E3158 and the measured air leakage shall be area-weighted by the surface areas of the building thermal envelope in each portion. The weighted average tested air leakage shall not be greater than the whole building leakage limit. The following portions of the building shall be tested:

1.1                     The entire building thermal envelope area of stories that have any conditioned spaces directly under a roof.

1.2                     The entire building thermal envelope area of stories that have a building entrance, a floor over unconditioned space, or a loading dock, or that are below grade.

1.3                     Representative above-grade portions of the building totaling not less than 25 percent of the wall area enclosing the remaining conditioned space.

2. Hospital, Museum and other occupancies approved by the commissioner may be permitted to satisfy the requirements of this section  by performing a pressurization test.

C402.6.2.2 Building thermal envelope design and construction verification criteria. The installation of the continuous air barrier shall be verified by the building official, a registered design professional or approved agency in accordance with the following:

1.                     A review of the construction documents and other supporting data shall be conducted to assess compliance with the requirements in Section C402.6.1.

2.                     Inspection of continuous air barrier components and assemblies shall be conducted during construction to verify compliance with the requirements of Section C402.6.2.2.1 and C402.6.2.2.2. The air barrier shall remain accessible for inspection and repair.

3.                     A final inspection report shall be provided for inspections completed by the registered design professional or an approved agency. The inspection report shall be provided to the building owner or owner’s authorized agent and the building official. The report shall identify deficiencies found during inspection and details of corrective measures taken.

C402.6.2.2.1 Materials. Materials with an air permeability not greater than 0.004 cfm/ft² (0.02 L/s × m²) under a pressure differential of 0.3 inch (7.6 mm) water gauge (75 Pa) when tested in accordance with ASTM E2178 shall comply with this section. Materials in Items 1 through 16 shall be deemed to comply with this section, provided that joints are sealed and materials are installed as air barriers in accordance with the manufacturer’s instructions:

1.                     Plywood with a thickness of not less than ³/₈ inch (9.5 mm).

2.                     Oriented strand board having a thickness of not less than ³/₈ inch (9.5 mm).

3.                     Extruded polystyrene insulation board having a thickness of not less than ¹/₂ inch (12.7 mm).

4.                     Foil-back polyisocyanurate insulation board having a thickness of not less than ¹/₂ inch (12.7 mm).

5.                     Closed-cell spray foam having a minimum density of 1.5 pcf (2.4 kg/m³) and having a thickness of not less than 1.5 inches (38.1 mm).

6.                     Open-cell spray foam with a density between 0.4 and 1.5 pcf (6 and 2.4 kg/m³) and having a thickness of not less than 4.5 inches (114.3 mm).

7.                     Exterior or interior gypsum board having a thickness of not less than ¹/₂ inch (12.7 mm).

8.                     Cement board having a thickness of not less than ¹/₂ inch (12.7 mm).

9.                     Built-up roofing membrane.

10.                     Modified bituminous roof membrane.

11.                     Single-ply roof membrane.

12.                     A Portland cement/sand parge, or gypsum plaster having a thickness of not           

less than ⁵/₈ inch (15.9 mm).

13.                     Cast-in-place and precast concrete.

14.                     Fully grouted concrete block masonry.

15.                     Sheet steel or aluminum.

C402.6.2.2.2 Assemblies. Assemblies of materials and components with an average air leakage not greater than 0.04 cfm/ft² (0.2 L/s × m²) under a pressure differential of 0.3 inch (7.6 mm) of water gauge (75 Pa) where tested in accordance with ASTM E2357, ASTM E1677, ASTM D8052 or ASTM E283 shall comply with this section. Assemblies listed in Items 1 through 3 below shall be deemed to comply, provided that joints are sealed and the requirements of Section C402.6.1.2 are met:

1.                     Concrete masonry walls coated with either one application of block filler or 2 applications of a paint or sealer coating.

2.                     Masonry walls constructed of clay or shale masonry units with a nominal width greater than or equal to 4 inches (101.6 mm).

3.                     A Portland cement/sand parge, stucco or plaster not less than 1/2 inch (12.7 mm) in thickness.

Section C402.6.4 Doors and access openings to shafts, chutes, stairways and elevator lobbies.  

Section C402.6.4 - Revise Exceptions 1 and 2 from Section C402.6.4 to read as follows:

Exceptions:

1.                     Door openings required to comply with the duct and air transfer opening requirements of the New York City Building Code.

2.                     Doors and door openings required to comply with UL 1784 by the New York City Building Code.

Section C402.6.6 Vestibules. 

Section C402.6.6 - Revise all the exceptions from Section C402.6.6 to read as follows:

Exceptions: Vestibules are not required for the following:

1.                     Doors not intended to be used by the public, such as doors to mechanical or electrical equipment rooms, or intended solely for employee use.

2.                     Doors opening directly from a sleeping unit or dwelling unit.

3.                     Doors that open directly from a space less than 3000 square feet (278.7 m²) in area, in buildings less than 75 feet (22.9 m) in height.

4.  Revolving doors.

5.                     Doors used primarily to facilitate vehicular movement or material handling and adjacent personnel doors.

6.                     Doors that open directly from a space less than 1000 square feet (92.9 m²) in area, in buildings 75 feet (22.9 m) and greater in height.

Section C402.7 Thermal bridges in above-grade walls. 

Section C402.7 - Delete Section C402.7, Section C402.7.1, Section C402.7.2, Section C402.7.3, Section C402.7.4 and Section C402.7.5 in their entirety and add new C402.7, Section C402.7.1, Section C402.7.2, Section C402.7.2.1, Section C402.7.2.2, Section C402.7.2.3, Section C402.7.2.4, Section C402.7.2.4.1 and Section C402.7.2.5 to read as follows:

C402.7 Thermal bridging documentation and mitigation.  Where present, intersections listed in Section C402.7.1 that create thermal bridges shall be detailed in construction documents. Thermal bridges shall be mitigated in accordance with Section C402.7.2.

Exceptions:

1.                     Assemblies not enclosing conditioned space.

2.                     Clear field thermal bridges.

3.                     Thermal bridges in uninsulated assemblies.

4.                     Linear- and point thermal bridges having a material thermal conductivity less than 3.0 Btu•in/h•ft²•°F (0.433 W/(m•K)).

5.                     Alterations except as required under section C503

C402.7.1 Thermal bridge details.  The following intersections shall be evaluated for thermal bridges and be detailed in construction documents:

1.                     Structural framing and members.

2.                     Cladding attachment systems

3.                     Assembly intersections:

a.                     Roof edge, parapet

b.                     Intermediate floor to wall intersection

c.                     Intermediate floor balcony or overhang to opaque wall intersection

d.                     Intermediate floor balcony in contact with vertical fenestration

e.                     Cladding support

f.                     Wall to vertical fenestration intersection

C402.7.2 Thermal bridges in above-grade walls. Thermal bridges in above-grade walls shall comply with this section or an approved design accordance with Section 102.

Exceptions: Blocking, coping, flashing, and other similar materials for attachment of roof coverings.

C402.7.2.1 Balconies and floor decks.  Balconies and concrete floor decks shall not penetrate the building thermal envelope. Such assemblies shall be separately supported or shall be supported by structural attachments or elements that minimize thermal bridging through the building thermal envelope.

Exceptions: Balconies and concrete floor decks shall be permitted to penetrate the building thermal envelope where one of the following applies:

1.                     An area-weighted U-factor is used for above-grade wall compliance which includes a U-factor of 0.8 Btu/h•ft²•°F (1.38W/m × K)  for the area of the above-grade wall penetrated by the concrete floor deck in accordance with Section C402.1.2.1.5.

2.                     An approved thermal break device with an R-value of not less than R-10 insulation material is installed in accordance with the manufacturer's instructions.

3.                     An approved design in accordance with Section 102 where the above-grade wall U-factor used for compliance accounts for all balcony and concrete floor deck thermal bridges.

C402.7.2.2 Cladding supports.  Linear elements supporting opaque cladding shall be offset from the structure with attachments that allow the continuous insulation, where present, to pass behind the cladding support element except at the point of attachment.

Exceptions:

1. An approved design in accordance with Section 102 where the above-grade wall U-factor used for compliance accounts for the cladding support element thermal bridge.

2. Anchoring for curtain wall and window wall systems where curtain wall and window wall systems comply with Section C402.7.2.4.

C402.7.2.3 Structural beams and columns. Structural steel and concrete beams and columns that project through the building thermal envelope shall be covered with not less than R-5 insulation for not less than 2 feet (609.6 mm) beyond the interior or exterior surface of an insulation component within the building thermal envelope.

Exception:

1.Where an approved thermal break device is installed in accordance with the manufacturer's instructions.

2. An approved design in accordance with Section 102 where the above-grade wall U-factor used to demonstrate compliance accounts for the beam or column thermal bridge.

C402.7.2.4 Vertical fenestration. Vertical fenestration. Vertical fenestration intersections with above-grade walls shall comply with one or more of the following:

1.                     Where above-grade walls include continuous insulation, the plane of the exterior glazing layer or, for metal frame fenestration, a non-metal thermal break in the frame shall be positioned within 2 inches (50.8 mm) of the interior or exterior surface of the continuous insulation.

2.                     Where above-grade walls do not include continuous insulation, the plane of the exterior glazing layer or, for metal frame fenestration, a non-metal thermal break in the frame shall be positioned within the thickness of the integral or cavity insulation.

3.                     The surface of the rough opening, not covered by the fenestration frame, shall be insulated with insulation of not less than R-3 material or covered with a wood buck that is not less than 1.5 inches (38.1 mm) thick.

Exceptions:

1. Where an approved design in accordance with Section 102 for the above-grade wall U-factor used for compliance accounts for thermal bridges at the intersection with the vertical fenestration.

2. Doors.

C402.7.2.4.1 vertical fenestration with spandrels. Vertical fenestration with spandrels shall comply with one of the following:

1. For the intersection between vertical fenestration and opaque spandrel in a shared framing system, manufacturer's data for the spandrel U-factor shall account for thermal bridges.

2. Use Default values as listed in C303.1.5.

C402.7.2.5 Parapets. Parapets shall comply with one or more of the following as applicable:

1.                     Where continuous insulation is installed on the exterior side of the above-grade wall and the roof is insulated with insulation entirely above deck, the continuous insulation shall extend up both sides of the parapet not less than 2 feet (609.6 mm) above the roof covering or to the top of the parapet, whichever is less. Parapets that are an integral part of a fire-resistance rated wall, and the exterior continuous insulation applied to the parapet, shall comply with the fire resistance ratings of the building code.

2.                     Where continuous insulation is installed on the exterior side of the above-grade wall and the roof insulation is below the roof deck, the continuous insulation shall extend up the exterior side of the parapet to not less than the height of the top surface of the roof assembly.

3.                     Where continuous insulation is not installed on the exterior side of the above-grade wall and the roof is insulated with insulation entirely above deck, the wall cavity or integral insulation shall extend into the parapet up to the exterior face of the roof insulation or equivalent R-value insulation shall be installed not less than 2 feet (609.6 mm) horizontally inward on the underside of the roof deck.

4.                     Where continuous insulation is not installed on the exterior side of the above-grade wall and the roof insulation is below the roof deck, the wall and roof insulation components shall be continuous and adjacent to each other at the roof-ceiling-wall intersection.

5.                     Where a thermal break device with not less than R-10 insulation material aligned with the above-grade wall and roof insulation is installed in accordance with the manufacturer's instructions.

Exception: An approved design in accordance with Section 102 where the above-grade wall U-factor used for compliance accounts for the parapet thermal bridge.

SECTION C403

BUILDING MECHANICAL SYSTEMS

Section C403.1.3 Electric-resistance space heating.

Section C403.1.3 - Revise  exception 5 from Section C403.1.3 to read as follows:

5.                     Makeup air for commercial kitchen exhaust systems required to be tempered by Section 508 of the New York City Mechanical Code is permitted to be heated by electric resistance.

Section C403.2.2 Ventilation.

Section C403.2.2 - Revise Section C403.2.2 to read as follows:

C403.2.2 Ventilation. Ventilation, either natural or mechanical, shall be provided in accordance with Chapter 4 of the New York City Mechanical Code. Where mechanical ventilation is provided, the system shall provide the capability to reduce the outdoor air supply to the minimum required by Chapter 4 of the New York City Mechanical Code.

Section C403.3.4.1 Boiler oxygen concentration controls.

Section C403.3.4.1 - Delete the exception Section C403.3.4.1.

Section C403.3.5 Buildings with high efficiency space heating gas boiler systems. 

Section C403.3.5 - Add new Section C403.3.5 to read as follows:

C403.3.5 Buildings with high efficiency space heating gas boiler systems.  New buildings where space heating is served by one or more gas hot water boilers with a minimum thermal efficiency (Et) of 90 percent when rated in accordance with the test procedures in Table C403.3.2(6) shall comply with this section, unless otherwise approved by the authority having jurisdiction. The hot water distribution system shall be designed so that the coils and other heat exchangers are selected such that at outdoor design conditions, the hot water return temperature entering the boilers is 120°F (49°C) or less when the boiler is firing.  

Section C403.4.1.1 Heat pump supplementary heat. 

Section C403.4.1.1 - Revise item 1 from Section C403.4.1.1 to read as follows:

1.                     The vapor compression cycle cannot provide necessary heating energy to satisfy the thermostat setting where controls are installed such that supplementary heat shall operate only when the outdoor air temperature is less than 17°F (-8.3°C) and supplemental heat capacity does not exceed 25 percent of total the design load. 

Section C403.4.6 Demand responsive controls. 

Section C403.4.6 - Revise item 2 from  Section C403.4.6 to read as follows:

2.                     Automatically decreasing the zone operating heating set point by the following values: 1°F (0.5°C), 2°F (1°C), 3°F (1.5°C), and 4°F (2°C) while maintaining the minimum room temperature requirements of the New York City Building Code.

Section C403.4.6 - Revise exception 1 and 2 from  Section C403.4.6 to read as follows:

1. Group I occupancies in accordance with the New York City Building Code.

2. Group H occupancies in accordance with the New York City Building Code.

Section C403.6.1 Variable air volume and multiple-zone systems. 

Section C403.6.1 - Revise item 3 from  Section C403.6.1 to read as follows:

3.                     The outdoor airflow rate required to meet the minimum ventilation requirements of Chapter 4 of the New York City Mechanical Code.

Section C403.6.6 Multiple-zone VAV system ventilation optimization control. 

Section C403.6.6 - Revise Section C403.6.6 to read as follows:

C403.6.6 Multiple-zone VAV system ventilation optimization control.  Multiple-zone VAV systems with direct digital control of individual zone boxes reporting to a central control panel shall have automatic controls configured to reduce outdoor air intake flow below design rates in response to changes in system ventilation efficiency (Ev) as defined by the New York City  Mechanical Code.

Exceptions:

1.                     VAV systems with zonal transfer fans that recirculate air from other zones without directly mixing it with outdoor air, dual-duct dual-fan VAV systems, and VAV systems with fan-powered terminal units.

2.                     Systems where total design exhaust airflow is more than 70 percent of total design outdoor air intake flow requirements.

Section C403.7.1 Demand control ventilation.   

Section C403.7.1 - Revise Item 2 from Section C403.7.1 to read as follows:

2. Spaces larger than 250 square feet (23.2 m²) in Climate Zones 5 and 6 and spaces larger than 500 square feet (46.5 m²) in climate zone 4 that have a design occupant lo