With newer and smarter technological marvels hitting the marketplace daily, it seems reasonable to expect that something as basic as a house should do what it is intended to do. At a minimum, your house should be safe, durable, comfortable, healthy to breathe in, and energy efficient. But the fact is that you are quite likely to experience problems in your house such as mold, cold drafts, rotting roofs, polluted air, and high energy costs. Any one of these performance problems is an indication that your house is not performing as it should: It is sick, and it needs a diagnosis and cure.
While these performance failures are all distinct types of problems, they have a common cause. They stem from a failure to understand the complex, interactive system that is a home. Surprisingly, until the last 15 years, very little scientific research had been conducted into how homes and buildings actually function. Instead, builders and contractors relied almost totally on “knowledge” handed down through word of mouth in the trades. Then when things went wrong, they had little to tell them why. Their fixes were usually based not on an understanding of how homes really function, but on what was traditionally done. Sometimes these fixes worked; often they didn’t.
Compounding the problem, the traditional view of homes is that they are simply a set of components that are, for the most part, independent of each other. Too often, the separate components of a home are designed by people who don’t communicate with each other. The architect designs for aesthetic appeal but not for energy efficiency or even for long lasting performance. The framer builds the frame of the home for structural stability but not for airtightness. The mechanical contractor designs and installs the heating, air conditioning, and ducts but rarely thinks of the occupants’ needs for fresh air. The common insistence on seeing these construction “specialties” as separate can cause a host of home performance problems.
In the last 15 years, there has been a revolution in the science of diagnosing and curing sick buildings. Through the process of applying scientific methods and instruments to the study of buildings, scientists have come to realize that buildings are like people. They must keep moisture out via a continuous watertight skin. They must provide clean, fresh air for the occupants while at the same time maintaining comfortable temperatures. They must not take in too many toxins, and when toxins do get in they must be expelled quickly. Houses must also be affordable to live in.
Perhaps the most important realization has been that buildings–like people–function as a system. Building scientists and home performance specialists–a small but growing group of well-trained professionals–have measured and documented how all the different components in a home interact with and affect one another. When one part goes wrong, it will inevitably effect other parts that may seem on the surface to have no direct connection. We have come to know that the different parts of a house are as interdependent as the organs of a living being. Houses should therefore be designed and treated so that all the different parts of the system interact in a way that is beneficial, and they should be treated this way when they are sick.
Written by: Doug Garrett of Building Performance and Comfort in Texas
