President of LaLiberteOnline Inc. and a principal of Building Knowledge Inc., Mark LaLiberte is a highly regarded green building consultant who helps builders nationwide understand and apply proper building science construction principles to improve their homes. www.buildingknowledge.com; www.laliberteonline.com.
In my travels, I hear many construction myths. One of the most common is that new houses are “just too tight.” But can a house really be too tight? In my opinion, no. A tight house is a predictable house. It lets us determine indoor comfort and maintain structural integrity. A leaky house is unpredictable. It has its own peculiar personality, one that we can never fully understand or control.
I’ll cast my vote for a tight house every time—the tighter the better—but with one condition: Builders must understand and respect the rules of building science. That means installing distributed ventilation, selecting sealed combustion equipment for all systems using gas, oil, or wood, and managing the effects of weather on the enclosure.
Testing homes lets us define and quantify the level of tightness in a home. Diagnostic and testing professionals now have specialized equipment, such as blower doors, duct blasters, infrared imaging, and flow hoods, that provide reliable, verifiable measurements of how well a given home performs.
There are several reasons you need to test the tightness of your homes. One is to satisfy the guidelines for the energy-efficiency programs in which you may take part. Another is to give your trade contractors a benchmark used to design HVAC systems to that is often undervalued. Each person who works on your project needs clear, definable standards that will result in a level of satisfaction for the trade contractor as well as for you and your client. Using a combination of testing measures, performance standards, mockups, and even photos will help everyone succeed and keep your project goals clearly defined.