§ 28-1001.2.2 New York city amendments to the New York State-specific version of ASHRAE 90.1.
AC § 28-1001.2.2
2025 NYC ASHRAE 90.1 Section 3.1.1 Occupancy. Section 3.1.1 – Add new Section 3.1.1 to read as follows: 3.1.1 Occupancy. Occupancy classification and use shall be determined by Chapter 3 of the New York City Building Code. Section 3.2 Definitions. Section 3.2 – Delete the definition of “authority having jurisdiction” after the definition of “attic and other roofs.” Section 3.2 – Add the definition of “authority having jurisdiction,” after the definition of “attic and other roofs,” to read as follows: authority having jurisdiction: the commissioner or the commissioner's designee. Section 3.2 – Add the definition of “clear-field U-factor,” after the definition of “clear-field thermal bridge,” to read as follows: clear-field U-factor. thermal performance factor that accounts for clear-field thermal bridges. Section 3.2 – Add the definition of “demand responsive control,” and “ demand response signal,” after the definition of “demand control ventilation (DCV),” to read as follows: demand responsive control: a control capable of receiving and automatically responding to a demand response signal. demand response signal: a signal that indicates a price or a request to modify electricity consumption for a limited time period. Section 3.2 – Delete the definition of “labeled” after the definition of “kilowatt (kW).” Section 3.2 – Add the definition of “labeled,” after the definition of “kilowatt (kW),” to read as follows: labeled: see Section 28-101.5 of the Administrative Code. Section 3.2 – Add the definition of “pre-engineered metal building,” after the definition of “primary sidelighted area,” to read as follows: pre-engineered metal building: a pre-engineered metal building (PEMB) is a structure where 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. Section 3.2 – Add the definition of “spandrel panel,” after the definition of “space conditioning category,” 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 4 Administration and Enforcement. Section 4.2.1.1 New Buildings. Section 4.2.1.1 – Delete Section 4.2.1.1 in its entirety and replace with a new Section 4.2.1.1 to read as follows: 4.2.1.1 New Buildings. New buildings shall comply with Sections 4.2.2 through 4.2.5 and the provisions of: a. Sections 5, “Building Envelope”; 6, “Heating, Ventilating, and Air Conditioning”; 7, “Service Water Heating”; 8, “Power”; 9, “Lighting”; 10, “Other Equipment,” and 11, “Additional Efficiency Requirements; b. Section 12, “Energy Cost Budget Method”; or c. Normative Appendix G, “Performance Rating Method.” When using Normative Appendix G, new buildings, additions to existing buildings, and/or alterations shall comply with Section 4.2.1.1.1 and Section 4.2.1.1.2. Alterations to existing buildings shall comply with Section 4.2.1.1.1. Section 5 Building Envelope. Section 5.4.3.1.1. Section 5.4.3.1.2 – Delete Section 5.4.3.1.1 in its entirety and replace with a new Section 5.4.3.1.1 to read as follows: 5.4.3.1.1. New buildings shall comply with measured air leakage requirements in Section 5.4.3.1.4 and continuous air barrier design and installation verification program performed in accordance with Section 5.9.1.2. Section 5.4.3.1.2. Section 5.4.3.1.2 – Delete Section 5.4.3.1.2 in its entirety and replace with a new Section 5.4.3.1.2 to read as follows: 5.4.3.1.2. Reserved Section 5.4.3.1.4 Measured Air Leakage. Section 5.4.3.1.4 – Delete Section 5.4.3.1.4 in its entirety and replace with a new Section 5.4.3.1.4 to read as follows: 5.4.3.1.4 Measured Air Leakage. Where measured air leakage is used for compliance, the rate of air leakage of the building envelope shall not exceed 0.35 cfm/ft 2 (1 L/s/m 2 ) under a pressure differential of 75 Pa (0.30 in. of water), with this air leakage rate normalized by the sum of the above-grade and below-grade building envelope areas of the conditioned space and semiheated space and in accordance with this section. a. Whole-building pressurization testing shall be conducted in accordance with ASTM E3158, ASTM E779, or ASTM E1827. Air leakage shall be measured following a multi-point regression method and then averaged from depressurization and pressurization tests. For buildings greater than 50 000 square feet (4645.2 m 2 ), 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, have a floor over unconditioned space, have a loading dock, or 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. Exception to 5.4.3.1.4(a): Hospitals, museums and other occupancies approved by the commissioner may be permitted to only perform pressurization test to comply with the requirements of this section. b. Where a building contains both conditioned space and semiheated space, compliance shall be shown using one of the following, as applicable: 1. Separately for the conditioned space and for the semiheated space, with the air leakage rate for the conditioned space normalized by the exterior building envelope area of the conditioned space and the air leakage rate for the semiheated space normalized by the semiexterior building envelope area of the semiheated space.
2.For the conditioned space and for the semiheated space together, with the air leakage rate for the overall space normalized by the sum of the exterior building envelope area and the semiexterior building envelope area minus the semiexterior building envelope area that separates the conditioned space from the semiheated space. c. Reporting shall be in compliance with Section 4.2.5.1.2. Section 5.5.3 Opaque Elements. Section 5.5.3 – Delete Section 5.5.3 in its entirety and replace with a new Section 5.5.3 to read as follows: 5.5.3 Opaque Elements. For all opaque elements, compliance with Tables 5.5-4 and 5.5-5 for each class of construction as described in Normative Appendix A, Sections A2 through A8, shall be demonstrated by 1 of the following 2 methods: a. Providing a minimum rated R-value of insulation added to the assembly equal to or greater than the insulation minimum R-value required of each insulation component. b. Providing insulation such that the maximum U-factor, C-factor, or F-factor for the entire assembly is not exceeded, as determined by 1 of the following: 1. Precalculated values in accordance with Normative Appendix A, Section A1.1.
3.When the total area of penetrations from through-the-wall equipment or equipment listed in Table 6.8.1-4 exceeds 1 percent of the opaque above-grade wall area, the mechanical equipment penetration area shall be calculated as a separate wall assembly with a default U-factor of 0.5, and compliance shall be shown with method b of this section. Where mechanical equipment has been tested in accordance with testing standards, and approved by the authority having jurisdiction, the mechanical equipment penetration area may be calculated as a separate wall assembly with the U-factor as determined by such test.
4.For opaque assemblies in curtain wall framing or other fenestration framing systems, compliance shall be shown using the effective U-factor values of Table 5.5.3. Table 5.5.3 Effective U-factors for Spandrel Panels and Glass Curtain Walls a Table 5.5.3 – Add a new Table 5.5.3 to read as follows: Table 5.5.3 Effective U-factors for Spandrel Panels and Glass Curtain Walls a RATED R-VALUE OF INSULATION BETWEEN FRAMING MEMBERSNoneR-4R-7R-10R-15R-20R-25R-30Frame TypeSpandrel PanelDefault U-factorRATED R-VALUE OF INSULATION BETWEEN FRAMING MEMBERSNoneR-4R-7R-10R-15R-20R-25R-30Frame TypeSpandrel PanelDefault U-factorAluminum without thermal break bSingle glass pane, stone, or metal panelU-0.445U-0.285U-0.259U-0.247U-0.236U-0.230U-0.226U-0.224Double glazing with no low-e coatingsU-0.356U-0.273U-0.254U-0.244U-0.234U-0.229U-0.226U-0.223Triple glazing or double glazing with low-e glassU-0.313U-0.263U-0.249U-0.241U-0.233U-0.228U-0.225U-0.223Aluminum with thermal break cSingle glass pane, stone, or metal panelU-0.429U-0.243U-0.212U-0.197U-0.184U-0.176U-0.172U-0.169Double glazing with no low-e coatingsU-0.328U-0.228U-0.205U-0.193U-0.182U-0.175U-0.171U-0.168Triple glazing or double glazing with low-e glassU-0.277U-0.217U-0.199U-0.189U-0.180U-0.174U-0.170U-0.167Structural glazing dSingle glass pane, stone, or metal panelU-0.428U-0.217U-0.180U-0.161U-0.145U-0.136U-0.130U-0.126Double glazing with no low-e coatingsU-0.316U-0.199U-0.172U-0.157U-0.143U-0.135U-0.129U-0.126Triple glazing or double glazing with low-e glassU-0.257U-0.186U-0.165U-0.152U-0.140U-0.133U-0.128U-0.125No framing or insulation is continuous eSingle glass pane, stone, or metal panelU-0.445U-0.160U-0.108U-0.082U-0.058U-0.045U-0.037U-0.031Double glazing with no low-e coatingsU-0.356U-0.147U-0.102U-0.078U-0.056U-0.044U-0.036U-0.030Triple glazing or double glazing with low-e glassU-0.313U-0.139U-0.098U-0.076U-0.055U-0.043U-0.035U-0.030 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 three-quarters inch (19.1 mm) air gap and five-eighths inch (15.9 mm) 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 interior exterior. e. This frame type shall be used for systems where there is no framing, or where the insulation is continuous across and uninterrupted by the framing (also known as mullion wrap). Table 5.5-4 Building Envelope Requirements for Climate Zone 4 (A,B,C) * Table 5.5-4 – Revise Table 5.5-4 to read as follows: Table 5.5-4 Building Envelope Requirements for Climate Zone 4 (A,B,C)* NonresidentialResidentialSemiheatedOpaque ElementsAssembly MaximumInsulation Min. R-Value Assembly MaximumInsulation Min. R-ValueAssembly MaximumInsulation Min. R-ValueNonresidentialResidentialSemiheatedOpaque ElementsAssembly MaximumInsulation Min. R-Value Assembly MaximumInsulation Min. R-ValueAssembly MaximumInsulation Min. R-ValueRoofsInsulation entirely above deckU-0.030R-33 c.iU-0.030 R-33 c.i.U-0.093R-10 c.i.Pre-Engineered Metal building aU-0.035R-19 + R-11 Ls or or R-25 + R-8 LsU-0.035 R-19 + R-11 Ls or R-25 + R-8 LsU-0.082R-19Attic and otherU-0.020R-53caU-0.020R-53caU-0.034R-30Walls, above GradeMassU-0.099R-11.2 c.iU-0.086R-13.25 c.i.U-0.580NRPre-Engineered Metal buildingU-0.048R-13ca + R-14.9 c.i.U-0.048R-13ca + R-14.9 c.i.U-0.162R-13Steel-framedU-0.061R-13ca + R-8.5 c.i.U-0.061R-13ca + R-8.5 c.iU-0.124R-13Wood-framed and otherU-0.061R-13ca + R-4.5 c.i. or R-19ca+R-1.5ci U-0.061 R-13ca + R-4.5 c.i. or R-19ca+R-1.5ciU-0.089R-13Wall, below GradeBelow-grade wallC-0.119R-7.5 c.i.C-0.092R-10 c.i.C-1.140NRFloorsMassU-0.057R-14.6 c.i.U-0.051 R-16.7 c.i.U-0.107R-6.3 c.i.Steel joistU-0.033R-38caU-0.033 R-38caU-0.052R-19Wood-framed and otherU-0.033R-30caU-0.033 R-30caU-0.051R-19Slab-on-Grade FloorsUnheatedF-0.520R-15 for 24 in.F-0.520 R-15 for 24 in.F-0.730NRHeatedF-0.843R-20 for 48 in. +%-5 full slab F-0.63 R-20 for 48 in.+R-5 full slabF-0.900R-10 for 24 in.Opaque DoorsSwingingU-0.370U-0.370U-0.370NonswingingU-0.310U-0.310U-0.360 FenestrationAssembly Max. UAssembly Max. SHGCAssembly Min. VT/SHGCAssembly Max. UAssembly Max. SHGCAssembly Min. VT/SHGCAssembly Max. UAssembly Max. SHGCAssembly Min. VT/SHGCFenestrationAssembly Max. UAssembly Max. SHGCAssembly Min. VT/SHGCAssembly Max. UAssembly Max. SHGCAssembly Min. VT/SHGCAssembly Max. UAssembly Max. SHGCAssembly Min. VT/SHGCVertical Fenestration, 0% to 40% of WallNonmetal framing, all0.280.361.10(for all types)0.280.361.10(for all types)0.50NR(for all types)NR(for all types)Metal framing, fixed, below 95 ft c0.300.360.300.360.50Metal framing, fixed, above 95 ft c0.360.360.360.360.50Metal framing, operable, below 95 ft c0.400.330.400.330.65Metal framing, operable, above 95 ft c0.420.330.420.330.65Entrance door0.630.330.630.330.77Skylight, 0% to 3% of RoofAll types0.480.38NR0.480.38NR0.75NRNR * The following definitions apply: c.i. = continuous insulation (see Section 3.2), ca= cavity insulation, FC = filled cavity (see Section A2.3.2.5), Ls = liner system (see Section A2.3.2.4); NR = no (insulation)requirement. a. When using the R-value compliance method for metal building roofs, a thermal spacer block is required (see Section A2.3.2). b. Exception to Section 5.5.3.2 applies for mass walls above grade. c. Where any portion of the fenestration frame is installed at or above 95 feet (29 m) above grade, the unit may meet the requirements for above 95 feet (29 m). Section 5.5.4.2.1 Vertical Fenestration Area. Section 5.5.4.2.1 – Revise Section 5.5.4.2.1 to read as follows: 5.5.4.2.1 Vertical Fenestration Area. The total vertical fenestration area shall not be greater than that specified in Table 5.5-4. Exception to 5.5.4.2.1: Vertical fenestration complying with Section 5.5.4.4.1, Exception 3. Section 5.5.4.2.2 Maximum Skylight Fenestration Area. Section 5.5.4.2.2 – Revise Section 5.5.4.2.2 to read as follows: 5.5.4.2.2 Maximum Skylight Fenestration Area. The total skylight area shall not be greater than that specified in Tables 5.5-4. Exception to 5.5.4.2.2: The total skylight area is permitted to be increased to no greater than 6 percent of the gross roof area, provided the skylights meet all of the criteria in Section 5.5.4.4.2, Exception 1, and the total daylight area under skylights is a minimum of half the floor area of the space. Section 5.5.4.3 Fenestration U-Factor. Section 5.5.4.3 – Revise Section 5.5.4.3 to read as follows: 5.5.4.3 Fenestration U-Factor: Fenestration shall have a U-factor not greater than that specified in Tables 5.5-4. Exception to 5.5.4.3: The U-factor for skylights is permitted to be increased to no greater than 0.90 Btu/h·ft 2 ·°F in Climate Zones 0 through 3 and 0.75 Btu/h·ft 2 ·°F in Climate Zones 4 through 8, provided the skylights meet all of the criteria in Section 5.5.4.4.2, Exception 1. Section 5.5.4.4.1 SHGC of Vertical Fenestration. Section 5.5.4.4.1 – Revise the first sentence of Section 5.5.4.4.1 to read as follows: Vertical fenestration shall have an SHGC not greater than that specified in Table 5.5-4. Section 5.5.4.4.2 SHGC of Skylights. Section 5.5.4.4.2 – Revise the first sentence of Section 5.5.4.4.1 to read as follows: Skylights shall have an SHGC not greater than that specified in Table 5.5-4. Section 5.5.4.5 Fenestration Orientation. Section 5.5.4.5 – Revise Section 5.5.4.5 to read as follows: 5.5.4.5 Fenestration Orientation. The vertical fenestration shall comply with either (a) or (b): a. For Climate Zones 0 through 8, AW = (AT )/4 and AE = (AT )/4 b. For Climate Zones 0 through 3, AW × SHGCW = (AT × SHGCC )/4 and AE × SHGCE = (AT × SHGCC )/4 For Climate Zones 4 through 8, AW × SHGCW = (AT × SHGCC )/5 and AE × SHGCE = (AT × SHGCC )/5 where AW = west-oriented vertical fenestration area AE = east-oriented vertical fenestration area AT = total vertical fenestration area SHGCC = SHGC criteria in Tables 5.5-4 for each climate zone SHGCE = SHGC for east-oriented fenestration that complies with Section 5.5.4.4.1 SHGCW = SHGC for west-oriented fenestration that complies with Section 5.5.4.4.1 Exceptions to Section 5.5.4.5: 1. Vertical fenestration that complies with Section 5.5.4.4.1, Exception (3).
5.Buildings in Climate Zone 8. Section 5.5.4.6 Visible Transmittance/SHGC Ratio. Section 5.5.4.6 – Revise the first sentence of Section 5.5.4.6 to read as follows: Where automatic daylighting controls are required in accordance with Section 9.4.1.1(e) or (f), fenestration shall have a ratio of VT divided by SHGC not less than that specified in Table 5.5-4 for the appropriate fenestration area. Section 5.5.5 Linear Thermal Bridges and Point Thermal Bridges. Section 5.5.5 – Revise Section 5.5.5 to read as follows: 5.5.5 Linear Thermal Bridges and Point Thermal Bridges. Where linear thermal bridges and point thermal bridges occur as described in Sections 5.5.5.1 through 5.5.5.5, they shall: a. Comply with the applicable requirements of Sections 5.5.5.1 through 5.5.5.5; or b. Not exceed the mitigated psi-factors and chi-factors in Table A10.1, where the psi-factors and chi-factors for the thermal bridges are determined in accordance with Normative Appendix A, Section A10. For the purposes of Section 5.5.5, linear elements that are connected to the building structure by a series of point connections shall be permitted to be characterized as linear thermal bridges or as individual point thermal bridges. Exceptions to 5.5.5: 1. Reserved 2. Semiheated spaces.
6.Alterations to existing buildings other than additions.
7.Roofs that project over exterior walls. Informative Note: For linear thermal bridges and point thermal bridges that fall under the provisions of Section 4.2 and cannot comply prescriptively with the provisions of Sections 5.5.5.1 through 5.5.5.4, projects can use Section 5.5.5.5, Normative Appendix C, or Normative Appendix G. Section 5.5.5.1.1 Roof Edges. Section 5.5.5.1.1 – Revise Section 5.5.5.1.1 to read as follows: 5.5.5.1.1 Roof Edges. At roof edges without parapets or overhangs, the roof insulation and the wall insulation shall comply with the following, as applicable to the location of the insulation: a. Where a wall has exterior continuous insulation, the roof insulation shall extend to the exterior of the wall insulation, and the wall insulation shall extend to the roof insulation. b. Where a wall has cavity or integral insulation that represents more than 50 percent of the total wall insulation R-value, the roof-to-wall insulation shall comply with 1 of the following: 1. The cavity or integral insulation shall extend to the underside of the roof insulation.
8.Systems expected to operate less than 20 hours per week at the outdoor air percentage covered by Table 6.5.6.1.2-1.
9.Indoor pool dehumidifiers meeting Section 6.5.6.4. Section 6.6.2.2 Criteria. Section 6.6.2.2 – Revise Section 6.6.2.2 to read as follows: Editor's note: L.L. 2026/047 did not provide any text for Section 6.6.2.2. Section 6.7.3.4 System Balancing. Section 6.7.3.4 – Delete Section 6.7.3.3, Section 6.7.3.3.1, Section 6.7.3.3.2, and Section 6.7.3.3.3, and add new Section 6.7.3.3, Section 6.7.3.3.1, Section 6.7.3.4, Section 6.7.3.4.1, Section 6.7.3.4.2, Section 6.7.3.4.3, Section 6.7.3.5, Section 6.7.3.5.1, Section 6.7.3.5.2, Section 6.7.3.5.3, Section 6.7.3.5.4, Section 6.7.3.5.4.1, Section 6.7.3.5.4.2, Section 6.7.3.5.5, Section 6.7.3.5.5.1, Section 6.7.3.5.5.2, Section 6.7.3.5.5.3, and Section 6.7.3.5.5.4 in their entirety. 6.7.3.3 Mechanical, renewable energy, and service water heating systems commissioning and completion requirements. Prior to passing the final mechanical and plumbing inspections, the approved agency shall provide evidence of mechanical systems commissioning and completion in accordance with the provisions of this section. Construction document notes shall clearly indicate provisions for commissioning and completion requirements in accordance with this section and are permitted to refer to specifications for further requirements. Copies of all documentation shall be given to the owner or owner’s authorized agent and made available to the building official upon request, in accordance with Sections 6.7.3.5.4 and 6.7.3.5.5. Mechanical systems, renewable energy, and service water heating systems shall include at a minimum, but are not limited to, the following heating, ventilating, air conditioning, service water heating, indoor air quality, and refrigeration systems (mechanical and/or passive) and associated controls: a. Heating, cooling, air handling and distribution, ventilation, and exhaust systems, and their related air quality monitoring systems. b. Air, water, and other energy recovery systems. c. Manual or automatic controls, whether local or remote, on energy using systems including but not limited to temperature controls, setback sequences, and occupancy based control, including energy management functions of the building management system. d. Plumbing, including insulation of piping and associated valves, domestic and process water pumping, and mixing systems. e. Mechanical heating systems and service water heating systems. f. Refrigeration systems. g. Renewable energy and energy storage systems. h. Other systems, equipment, and components that are used for heating, cooling, or ventilation and that affect energy use. Exceptions to 6.7.3.3: 1. Mechanical systems and service hot water systems in new buildings, additions, or alterations where either the total mechanical equipment capacity being installed or the total mechanical equipment connected load serving the alteration space is less than 480,000 Btu/h (140.7 kW) cooling capacity and 600,000 Btu/h (175.8 kW) combined service water-heating and space-heating capacity.
