The New NYC Airtightness Requirement, Explained

NYC's 2025 Energy Conservation Code sets a hard air leakage limit of 0.40 CFM/ft2 at 75 Pascals, verified through staged testing while walls are still open.

Architects and contractors used to a single end-of-job blower-door test now have to build intermediate testing checkpoints into the schedule, or risk reopening finished walls to chase a failed test.

Sequence staged air leakage tests at sheathing, rough-in, and enclosure, with the architect, envelope consultant, and contractor each owning a specific part of the coordination.

Positions PUR4 as an architectural partner for NYC teams navigating the 2025 NYCECC airtightness requirement, drawing on Passive House envelope detailing experience.

Projects that plan staged testing into the schedule from the start treat each test as a checkpoint. Projects that treat airtightness as an afterthought lose schedule time reopening finished work.

The airtightness requirement needs to show up in the construction schedule before it shows up as a testing line item, with an envelope consultant involved from design, not after a failed test.