The two types of windows are operable (those that open) and fixed (those that don’t).  Fixed windows tend to be more energy efficient because they are sealed on all four sides and have no moving parts.  However, it is often desirable and required by BC building Code to have some operable windows for ventilation and for use as emergency exits.

Operable windows come in several styles:

Frames & sashes come in several material types:

• Aluminum is strong & durable, requires little maintenance and resists warping.  However, aluminum frames & sashes must be designed with significant thermal breaks to reduce heat loss by conduction.
• Fibreglass offers excellent thermal performance, is durable & requireds minimal maintenance.  Hollow sections of the frame & sash may be filled with foam insulation to further reduce heat loss.
• Vinyl provides good thermal performance and is easy to maintian.  Large units may need reinforcement to increase their strength, and some reinforcing materials can increase conductive heat loss.  Hollow sections of vinyl frames can be filled with foam insulation.
• Solid wood has good insulating value and structural strength but requires protection from the weather, either through regular painting or staining or the use of low-maintenance, factory-applied claddings and finishes.