Blower Door equipment is utilized to conduct objective testing of the building envelope for air tightness. This comprehensive test confirms proper build practises during construction. Normally there would be 2 blower door tests completed during the build process. The first test is run when the building envelope including windows, and doors and there is no exterior or drywall finishes installed. This provides the baseline for the home. The second is done upon completion of the exterior and interior. This allows the discovery of any issues created by installation of equipment. The impact to build is that you get the observation of your actual Air Changes per Hour (ACH) measurement. The lower the air changes the less operating cost to the owner for energy to heat or cool the building. Building code minimums do not provide a good baseline for an Net Zero or truly low energy cost home. The target should be to reduce ACH to below the required fresh air requirement of 2.5 ACH by building code. If the building leaks are below 2.5 ACH (Targets should be <1.0) then you are truly controlling as much of the air changes through your HRV (Heat Recovery Ventilation unit) and recovering the energy from that air that you just heated or cooled. The HRV takes the heat/cool from the air it is exhausting and puts it into the air it is bringing into the home, therefore saving you energy dollars. If the house is leaking by itself, then none of the energy is captured and you have to re-heat or cool that air again. Costing you money.
We also use the final blower door test to complete the ACH (Air Changes per Hour) official testing for building permit sign off. This service is required anyway and we include it in the price.