A building enclosure includes the roof, walls, openings, and below ground materials that separate the building from its surrounding environment. It functions to control, support, distribute, and beautify. All of these functions are important to both the comfort and safety of the occupants, to the perceived beauty of the building, and to the extended life of the building itself.

1. Controls:

• Rain and snow penetration
• Pollution, dust, other contaminants or environmental hazards  
• Heat flow
• Airflow, including wind
• Water vapor 
• Groundwater
• Light 
• Solar radiation
• Fire
• Noise
• Entrance of animals, bugs, vermin
• Entrance of unwanted humans
• Odors  

2. Supports the building and its components.

3. Distributes utilities and other services.

4. Beautifies (or not) both the interior and exterior of the home through the finish out and decorative components and cladding.