The building envelope is the exterior shell of a building—walls, roof, foundation, windows, doors, and insulation—that controls heat, air, and moisture flow. A strong envelope improves energy efficiency, comfort, and sustainability.

A well-designed building envelope:

• Reduces heat loss in winter and heat gain in summer
• Lowers energy use by reducing the need for heating and cooling
• Improves occupant comfort by reducing drafts, moisture issues, and temperature swings
• Supports healthy indoor air quality by controlling airflow and moisture
• Enhances durability by preventing condensation and material degradation

In many buildings, most wasted energy comes from air leaks, poor insulation, or inefficient windows—problems with the envelope.