Blower Door Testing for Occupancy

A blower door test evaluates the airtightness of a building and is a code requirement for all new construction before obtaining a Certificate of Occupancy (COO). This applies to residential homes and apartments/condos under four stories. The code mandates an air leakage rate of 4 Air Changes per Hour (ACH) at 50 Pascals of pressure, which can be a challenging standard—especially if the building wasn’t designed with this requirement in mind.

Why is the test necessary?

The energy code enforces airtight construction because it reduces energy consumption and enhances comfort. While tightly sealed buildings require mechanical ventilation, the benefits include lower energy costs, improved indoor air quality, and better climate control.