House as a System
What is the "House as a System" Concept?
All the different components of a house, including insulation, ventilation, draftproofing, windows, doors and control systems, are interconnected. The goal is to keep everything in balance. A change to one part of the system will affect other parts of the system.
For example, properly installed energy-efficient windows will reduce the amount of heat that escapes from a house by minimizing the direct transfer of heat and reducing air leakage around and within the window frame. However, this reduction in uncontrolled air leakage can also trap moisture within the home. Therefore, an improved ventilation system such as a dehumidistat controlled bathroom fan may now be required to remove excess moisture from the home in a controlled manner.
If energy savings are an important goal in your renovations, then changing windows alone may not meet your needs. If your crawlspace has no insulation, more heat may now be lost through your floors. One action can create an imbalance in your home.
The house-as-a-system approach will help to minimize problems.
House-as-a-System Home Improvements
When planning home improvements, especially those affecting the systems mentioned above, we recommend that you look for a contractor who will take into account how a home works as a system, and carry out renovations to preserve a healthy and comfortable indoor environment.
A "house as a system"-oriented contractor will:
- use a blower door test to locate areas of major air leakage in order to maximize draftproofing while ensuring adequate ventilation
- upgrade mechanical equipment with new, energy-efficient equipment – for example, programmable thermostats to save energy on heating, or quiet and efficient bathroom and kitchen fans for improved ventilation
- make the building envelope or shell more energy-efficient by adding insulation to the areas of greatest heat loss, and by weatherstripping and caulking gaps and cracks
- replace older inefficient windows with energy-efficient models – preferably with a low-E coating and argon gas fill
- replace old exterior doors with insulated steel ones
