Each component of a building needs to work with all the others - from structure and mechanicals, to openings and finishes. The house-as-a-system approach creates a more durable, more comfortable, and more energy efficient house.

The major component categories of the house-as-a-system approach are:

• The Building Envelope
• The Mechanical Systems
• The Occupants

The house is also influenced by climate and the surrounding environment - exposure to sun, wind, snow and rain, proximity of trees and waterways, pollutants from industry, traffic and noise. Each of these factors may influence the performance of the system as a whole.