Which Window Orientation is Best For Your Home?

Here is some honest truth, the windows in your home and building increase building costs, energy use, maintenance and are essentially bad for the environment. While they are the weak link of the building envelope, they hold a strong fondness to our hearts and desires. Good design plan for your home or building has balance and is capable of boosting performance.

The key to beneficial window placement in your home you need to have a balance of Total Window Area and Directional Orientation.

Total Window to Floor Area.

It is believed that a 15% default of window to floor area is best for an average 2000 sqft home. Many homes have more glass, some less but it’s a fair average for comparisons. By paying attention to the directional orientation of the windows, we make significant impacts on heating and cooling performance of homes and buildings.

Orientation

Designing with the path of the sun is an easy way to maximize a home’s window investment. Here is a breakdown on the cardinal directions and how they affect window’s influences on architecture.

North

This is the most desirable direction for even, day-long light. It’s well known among artists for its accurate color rendering and lack of glare. Its a safe direction to have windows protected from overheating concerns. For best daylighting, overhangs should be minimal yet balanced with the rain protection benefits they provide. Covered porches over north facing windows will dramatically reduce natural light available to the inside.

North facing windows are the worst for heating performance. In the winter, they contribute almost nothing to solar heat gain. High performance windows are beginning to overcome these drawbacks and super performance triple pane windows are capable of contributing slightly more heat than they lose, even on the north sides of a home. For budgets wanting to stay balanced in heating performance, north-facing window quantities should be as modest as possible.

South

South is the most important direction for heating performance. By increasing south-facing window area you generate free heat, daylighting and passive survivability. Passive survivability, meaning the home rarely drops below 45-50F during extended winter power outages.

East

The direction for bedrooms or kitchens for early risers or those that appreciate morning sun. East windows in average situations have a neutral effect on overall energy performance, contributing morning heat in the winter and unwanted heat in the summer depending on shading, porches or overhangs, quantity of windows and SHGC.

West

This is typically the least efficient orientation in our climate. No direction contributes to overheating and discomfort like the west. Unshaded west walls without windows have a measurable negative influence, heated by the setting, summer sun. With windows involved, it gets much worse. Low SHGC glass, deep overhangs like those from covered porches and landscaping help control this orientation of most concern. It’s wise to reduce the quantity of west windows as much as possible in our mixed climate, especially if not well protected by covered porches or big, shade trees.