[{"data":1,"prerenderedAt":169},["ShallowReactive",2],{"guide-nyc-new-building-air-leakage-test-certificate-of-occupancy-en-US":3},{"guide":4,"related":150},{"title":5,"seoTitle":6,"description":7,"summary":8,"sections":9,"faq":113,"cta":129,"date":131,"updated":131,"service":132,"order":133,"sources":134,"slug":148,"locale":149},"NYC Air-Leakage Testing for New Buildings Under the 2025 Energy Code","NYC New Building Air-Leakage Test and the CO","The 2025 NYC Energy Code requires a third-party air-leakage test on every new building, and DOB will not issue the CO until it passes. How to plan for it.","Under the 2025 NYC Energy Conservation Code, which applies to complete energy submissions filed on or after March 30, 2026, every new building must pass a whole-building air-leakage test performed by a third party independent of the permit holder and observed by an approved progress inspection agency. On the commercial provisions the measured leakage may not exceed 0.35 cfm per square foot of building thermal envelope at 75 Pa. A building that fails must be sealed and retested, and DOB will not sign it off for a certificate of occupancy until the test passes. Most leaks are decided at framing and before drywall, so the test has to be planned from the start of construction, not at the end.",[10,47,52,65,77,105,109],{"heading":11,"paragraphs":12,"table":15,"after":45},"What the 2025 NYC Energy Code requires",[13,14],"DOB began enforcing the [2025 NYC Energy Conservation Code](https:\u002F\u002Fwww.nyc.gov\u002Fsite\u002Fbuildings\u002Fcodes\u002Fenergy-conservation-code.page) (2025 NYCECC) and 2025 NYC ASHRAE 90.1 on March 30, 2026. Complete applications filed on or before March 29, 2026 may continue under the 2020 NYCECC, provided the submission was complete, is diligently pursued and does not later undergo a material compliance change or a switch from a prescriptive path to an energy model. Incomplete applications filed before March 30, 2026 may be held to the 2025 code.","According to [DOB's NYCECC frequently asked questions](https:\u002F\u002Fwww.nyc.gov\u002Fsite\u002Fbuildings\u002Fcodes\u002Fnycecc-frequently-asked-questions.page), air-leakage testing is required for all new construction under the 2025 NYCECC, whether the project follows the residential or the commercial provisions. The project's Energy Analysis must identify the test standard, the approved third party, the building thermal envelope area, the maximum leakage rate that applies and any guarded or partial-building test approach the team intends to use.",{"caption":16,"head":17,"rows":20},"Air-leakage testing under the 2025 NYCECC, as stated by DOB as of October 2026",[18,19],"Topic","What DOB states",[21,24,27,30,33,36,39,42],[22,23],"Which buildings","All new construction, on the residential or the commercial provisions",[25,26],"Which filings","Complete energy submissions filed on or after March 30, 2026",[28,29],"Leakage limit, commercial provisions (C402.6.2)","No more than 0.35 cfm per square foot of building thermal envelope area at 75 Pa, unless another code path applies",[31,32],"Residential provisions","Separate R402.5 test method and target",[34,35],"Who tests","An approved third party independent of the permit holder",[37,38],"Who observes","An approved progress inspection agency under 1 RCNY 101-07",[40,41],"If the test fails","Leaks are found and corrected, and the building is retested",[43,44],"Certificate of occupancy","Not signed off until the air-leakage requirement is met",[46],"Which provisions apply to a given building, and therefore which target it must meet, is set by the energy professional of record in the Energy Analysis. Ask for that target in writing at the start of construction, because every trade that touches the envelope works toward it.",{"heading":48,"paragraphs":49},"The certificate of occupancy waits for a passing test",[50,51],"DOB's guidance is direct: a building that exceeds the allowed leakage rate must be sealed and retested until it meets the target, and it cannot be signed off, meaning it cannot obtain a certificate of occupancy, until the air-leakage requirement is met. The test is recorded among the energy code progress inspections on the TR8, and the [certificate of occupancy](https:\u002F\u002Fwww.nyc.gov\u002Fsite\u002Fbuildings\u002Fproperty-or-business-owner\u002Fcertificate-of-occupancy.page) itself requires final sign-offs, no open applications and no open violations.","A failed test at the end of a job is expensive because the leaks are by then behind finished walls, ceilings and cabinets. Each retest also has to be scheduled with the testing firm and the progress inspector. How a pending test interacts with a [temporary certificate of occupancy](https:\u002F\u002Fwww.nyc.gov\u002Fsite\u002Fbuildings\u002Fproperty-or-business-owner\u002Ftemporary-certificate-of-occupancy.page) on a particular job is a question to settle early with the design team and, where needed, with DOB. Our guide to [TCO and CO for new buildings](\u002Fguides\u002Fnyc-tco-vs-co-new-building) covers the rest of the closeout sequence.",{"heading":53,"paragraphs":54,"list":56,"after":63},"Where new apartment buildings leak",[55],"The test measures leakage through the building thermal envelope: exterior walls, the roof, the lowest floor and their openings. DOB notes that these requirements apply to envelope components, not to interior construction, and that the air barrier must be continuous across the envelope (C402.6.1). In a six-story building with thirty or so units, the envelope is crossed hundreds of times by pipes, ducts, conduits and line sets, and every crossing is a possible leak.",[57,58,59,60,61,62],"Penetrations through exterior walls and the roof: plumbing vents, kitchen and bath exhaust, dryer exhaust, heat pump line sets and condensate lines, electrical feeders, and low-voltage cabling.","Window and door rough openings, where the window membrane must lap onto the wall air barrier without gaps.","Transitions between assemblies: wall to roof, wall to foundation, slab edges at each floor, parapets and balcony connections.","Shafts, chases and the top of elevator and stair enclosures that connect to the roof.","Electrical boxes, panels and recessed fixtures set in exterior walls or top-floor ceilings.","Openings left by later work, such as a cable pulled through a sealed wall after the air barrier was inspected.",[64],"Fire-stopping and air sealing are separate requirements. Fire-stopping at rated walls, floors and shafts uses tested and listed systems to stop fire and smoke; the air barrier is a continuous layer of the envelope. A pipe that leaves a rated shaft and exits the building may need both, detailed and inspected separately. Treating one as a substitute for the other is a common reason a building fails late.",{"heading":66,"paragraphs":67,"list":69},"Planning for the test from framing",[68],"The test is passed or failed during framing and before drywall, when the air barrier and every penetration are still visible. DOB points to the air barrier documentation requirements of C402.6.1.1 and, for commercial work, to thermal-bridge documentation under C402.7. An air barrier continuity plan with a detail for each type of joint is the clearest way to give every trade the same instructions. The steps below keep the risk at the stage where it is cheap to correct.",[70,71,72,73,74,75,76],"Name the air-barrier responsibility in each trade contract, including who seals each type of penetration and with which approved material.","Review the envelope details with the architect, the energy professional and the trades before framing starts, with particular attention to windows, slab edges and roof transitions.","Keep a penetration log for each floor: what crosses the envelope, where, who installed it and who sealed it, with photographs.","Walk each floor before close-in with the trades that penetrate the envelope, and record the condition of the air barrier with photographs or a 3D scan.","Consider a preliminary test on a floor or a portion of the building while walls are still open, if the energy professional and the testing firm recommend one.","Set a rule that no new envelope penetration is made after inspection without notice, sealing and a photograph, and enforce it for every trade, including low-voltage and sprinkler work.","Book the final test with the third-party firm and the progress inspection agency well before the planned TCO date, with time for one round of sealing and a retest.",{"heading":78,"table":79,"after":103},"Who is responsible for what",{"caption":80,"head":81,"rows":84},"Typical responsibilities for the air-leakage test on a new building",[82,83],"Party","Role in the test",[85,88,91,94,97,100],[86,87],"Owner or developer","Engages the design team, the testing firm and the progress inspection agency, and holds the schedule for the test",[89,90],"Energy professional of record","Sets the compliance path and target in the Energy Analysis and the envelope details",[92,93],"Permit holder and general contractor","Builds the envelope to the details and coordinates all trades that penetrate it",[95,96],"Third-party testing firm","Performs the test; must be independent of the permit holder",[98,99],"Progress inspection agency","Observes the test and records the TR8 inspections; must avoid conflicts of interest",[101,102],"Finish and MEP trades","Seal their own penetrations to the approved details and keep the barrier intact after inspection",[104],"DOB requires the testing firm to be independent of the permit holder, and its rules bar progress inspectors from any financial interest in the work they inspect. The contractor who seals the building therefore cannot be the one who certifies the result.",{"heading":106,"paragraphs":107},"Ventilation and all-electric systems",[108],"A tighter envelope reduces uncontrolled air exchange, so the ventilation design matters more. Dedicated outdoor air through an energy or heat recovery ventilator is covered in our guide to [ERV, HRV and makeup air](\u002Fguides\u002Ferv-hrv-makeup-air-nyc). New buildings under seven stories in New York City must also be all-electric under Local Law 154, which our [guide to the NYC and state gas bans](\u002Fguides\u002Fnyc-ny-gas-ban-new-buildings) explains in detail. Heat pump line sets, condensate drains and exhaust terminations from an all-electric design add envelope penetrations, so they belong in the penetration log from the start.",{"heading":110,"paragraphs":111},"How we support the test",[112],"We perform interior framing, drywall, fire-stopping and air-sealing work on new apartment buildings, working under the general contractor's permit as a subcontractor, and we coordinate electrical, plumbing and mechanical scopes through licensed partner contractors. On our scopes we keep floor-by-floor penetration logs, photograph and 3D-scan walls before close-in, and correct the sealing items on our scopes ahead of the test date. As a contracted owner's representative we can also track the test schedule, the testing firm and the progress inspector alongside the rest of the [construction closeout](\u002Fservices\u002Fconstruction).",[114,117,120,123,126],{"q":115,"a":116},"Does the air-leakage test apply to a six-story apartment building?","Yes. Under the 2025 NYCECC, DOB requires air-leakage testing for all new construction, whether the building follows the residential or the commercial provisions. The 2025 code applies to complete energy submissions filed on or after March 30, 2026; a complete submission filed earlier may remain under the 2020 NYCECC, which has its own testing rules.",{"q":118,"a":119},"Who is allowed to perform the test?","DOB requires the test to be performed by an approved third party independent of the permit holder and to be observed by an approved progress inspection agency, as defined in 1 RCNY 101-07. The general contractor or a trade on the job cannot certify its own work.",{"q":121,"a":122},"What happens if the building fails?","The leaks must be found and corrected, and the building retested until it meets the required rate or another code-compliant resolution is approved. DOB will not complete the sign-off for the certificate of occupancy until the requirement is met.",{"q":124,"a":125},"Is the limit always 0.35 cfm per square foot?","That figure applies to whole-building testing under the commercial provisions, section C402.6.2, at 75 Pa, unless another code path applies. The residential provisions use separate R402.5 criteria, and projects on 2025 NYC ASHRAE 90.1 document testing under its section 5.4. The energy professional of record sets the applicable target in the Energy Analysis.",{"q":127,"a":128},"Can a drywall or finish contractor affect the result?","Yes. Electrical boxes in exterior walls, top-floor ceilings, cabinet and fixture fastenings, and any cable or pipe added after the air barrier was inspected can all create leaks. Each finish trade should seal its own penetrations to the approved details and record them before the walls are closed.",{"text":130},"For framing, drywall and air sealing planned around the test, and for interior finish packages, punch and turnover, closeout support and owner's-representative services on new apartment buildings, see [our services for developers](\u002Fdevelopers). Send the drawings and the energy analysis for a written estimate, which is provided at no charge.","2026-10-25","construction",137,[135,139,142,145],{"title":136,"url":137,"publisher":138},"NYCECC Frequently Asked Questions","https:\u002F\u002Fwww.nyc.gov\u002Fsite\u002Fbuildings\u002Fcodes\u002Fnycecc-frequently-asked-questions.page","NYC Department of Buildings",{"title":140,"url":141,"publisher":138},"Energy Conservation Code","https:\u002F\u002Fwww.nyc.gov\u002Fsite\u002Fbuildings\u002Fcodes\u002Fenergy-conservation-code.page",{"title":143,"url":144,"publisher":138},"Certificate of Occupancy","https:\u002F\u002Fwww.nyc.gov\u002Fsite\u002Fbuildings\u002Fproperty-or-business-owner\u002Fcertificate-of-occupancy.page",{"title":146,"url":147,"publisher":138},"Temporary Certificate of Occupancy","https:\u002F\u002Fwww.nyc.gov\u002Fsite\u002Fbuildings\u002Fproperty-or-business-owner\u002Ftemporary-certificate-of-occupancy.page","nyc-new-building-air-leakage-test-certificate-of-occupancy","en-US",[151,155,159,163],{"slug":152,"title":153,"description":154,"service":132,"date":131,"updated":131},"nyc-ny-gas-ban-new-buildings","NYC and New York State Gas Bans for New Buildings","How NYC Local Law 154 and the state All-Electric Buildings Act apply to new buildings and gut renovations, and the enforcement status on October 25, 2026.",{"slug":156,"title":157,"description":158,"service":132,"date":131,"updated":131},"nyc-tco-vs-co-new-building","TCO vs CO for a New NYC Apartment Building","What a temporary and a final certificate of occupancy each require for a new NYC building, what usually holds up closeout, and how TCO renewals work.",{"slug":160,"title":161,"description":162,"service":132,"date":131,"updated":131},"nyc-six-vs-seven-storeys-site-safety-rules","Site Safety Rules for Six- and Seven-Story Buildings in NYC","A NYC building of 7 stories or 75 feet is now a major building that needs a site safety manager. What changes, plus the 2026 superintendent and SST rules.",{"slug":164,"title":165,"description":166,"service":167,"date":168,"updated":131},"rental-turnover-cost-tips","Reducing turnover and maintenance costs on rental units","Practical ways for NYC and Long Island landlords to shorten vacancy and spend less on each turnover: standard finishes, durable materials and planned maintenance.","rental","2026-10-24",1792980727475]