Designing for Thermal Performance and Energy Efficiency

When it comes to a building’s internal temperature, comfort doesn’t always have to come at a cost.  Buildings designed to compliment the climate in which they’re built not only maximize thermal comfortability but also minimize energy consumption by regulating interior conditions through intentional design rather than reliance on electricity. For warmer regions that spend more on cooling than heating, achieving optimal thermal performance begins with avoiding unwanted heat gain and cooling expenses by considering the following:

  1. Building Orientation

How a building is oriented will determine how much sunlight each side will get and when. By positioning a building lengthwise across the east-west axis with the side with the most surface area facing north or south, an architect can reduce the building’s exposure to the rising and setting sun that is responsible for a much of a building’s solar heat gain.

  1. Glazing Selection

Glazing selection plays a major role in managing interior temperatures by regulating the transfer of heat or cold through an opening. With the right glazing, an architect can help keep the heat out and the cold in without exhausting the budget. Warmer climates benefit from products with a low solar heat gain coefficient (SHGC), the fraction of solar radiation transmitted through a window or skylight, as well as a low U-factor, the rate at which non-solar heat is conducted through a window or skylight. The lower the SHGC and U-factor, the more effective the product is at shading and insulating the interior – allowing natural daylight to pass through without the heat. Translucent glazing materials are also effective for east and west facing spaces where glare is a concern. Glazing selections with poor thermal performance will likely require additional shading devices.

  1. Room Arrangement

When arranging rooms within a building, it’s important to consider the room’s purpose and how that purpose may be affected by natural light. A room regularly occupied by workers or students needs access to daylight, but too much direct sunlight can also cause discomfort or difficulty seeing. Similarly, rooms with their own internal heat sources, such as certain electronics and appliances, can easily become overheated if not properly positioned. An optimal arrangement places these more “sun-sensitive” rooms facing north or south whereas rooms with fewer windows or occupants may be better positioned facing east or west.

  1. Window Placement

Because windows and skylights are the largest facilitators of solar heat gain, determining the size and placement for these openings is a critical decision for thermal performance. Windows offer many benefits– fresh air, natural daylight, views to the outside – but windows with transparent glazing, particularly those facing east or west exposed to low angles of the sun, can also be a source of uncomfortable hot spots and glare. In these situations, translucent materials, or a mix of transparent and translucent glazing, may be beneficial. North or south-facing windows may still require shading or deeper building overhangs, but avoid the Sun’s direct penetration.

  1. Ventilation Option:

Even the flow of warm air through a space can be cooling; and in warmer climates where a nice breeze through the building can reduce the need for air conditioning, ventilation can be an efficient way to keep occupants comfortable. In order for ventilation to work effectively, windows must be scaled and situated to allow air to flow freely from one end of the space to the other.

By taking these considerations into account when designing for hot climates, architects can maintain thermal comfort while also reducing the need for auxiliary cooling, cutting electric costs, and lowering carbon emission. For further guidance on thermal performance and choosing the right glazing selection for your project, contact Major’s sales team at 888-759-2678 or