A blower door test calculates the volume of air leakage within a building. The use of a blower door along with thermography can be very beneficial for the builder and most importantly for their clients.  

This is also used to locate wind-driven water leakage. A blower door and Thermal imaging are crucial in the new home construction or renovations before drywall is installed after the installation of the vapour barrier or spray foam application to identify areas of any air infiltration from the application process. Air infiltration can do more than having higher energy bills and discomfort, It can also cause possible mold growth and deterioration of building materials. Water exists in the air as a solid, liquid and gas. 

Description of Blower Door Testing
Diagram of Blower Door Testing
New Home Construction
New Home Construction Air Infiltration
Air Infiltration
New home construction showing air infiltration from the exterior door. 
Air Infiltration from Spray Foam Application
Spra Foam Air Infiltration
Air infiltration from Spray foam application that will need to be repaired prior to drywall. 
Blower Door Test, Pre-Drywall
New Home Construction Blower Door Test
Air Infiltration from Window
Air Infiltration Due to Manufacturer Defect
New home construction pre-drywall blower door test. The thermal image is showing air infiltration high lighted in yellow. 
The yellow arrow is pointing out the dark blue area is air infiltration from the window. This is a faulty window from the manufacturer from new home construction.