ARCHIVED - Building Envelope

Better quality windows, doors and insulation will help keep your utility costs down and also help reduce street noise   a particularly important factor in the hospitality industry. Building-envelope improvements are generally more cost-effective when they are conducted as part of new construction or major retrofits.

Windows

• Various window options improve on the relative energy inefficiency of single-pane standard glazing. These include double- and triple-pane glazing, tinted glazing, reflective glazing, spectrally selective glazing and insulated glazing with inert gas between the layers. Wood and vinyl frames are more energy efficient than aluminium. Storm-window systems reduce heat loss in winter.

• A more cost-effective option than new windows is the installation of solar glazing or reflective film inside existing windows. Energy savings can be as high as 25 percent, with approximate paybacks in less than three years.

• Daylighting panels are translucent units that diffuse the light throughout the space and reduce glare, with higher R-values than conventional windows.

• Other window coverings such as shutters, shades and draperies provide insulation benefits, especially in summer when they reduce the amount of sunlight   and heat   entering rooms.

Doors

• When replacing exterior doors, choose well-insulated, energy-efficient models.

• Revolving doors are the best choice for keeping wind and weather out of lobbies. Check these doors periodically to ensure there are no leaks along their edges or bottoms.

• High-quality weatherstripping that is durable and long lasting will assist in combating unwanted drafts.

• Install plastic secondary-door curtains inside delivery doors and bays.

Insulation

• Energy-efficient insulation types include fibre (usually available in loose-fill and batts) and foam (usually available in rigid sheets and sprays). Exterior reflective materials are also available, but offer poor insulation value.

• Seal air leaks and cracks by using foams, caulking and weatherstripping. Stuff fibreglass or glazier's foam backer rod insulation into areas too large to be caulked.

• Wall- and roof-insulation upgrades are best undertaken as part of larger renovation projects. Upgrades to insulation in basements and top-floor ceiling crawl spaces can be done anytime.

• If wet insulation is detected, replace it immediately once the source of the moisture has been identified and repaired.

Other Building-Envelope Measures

• Paint the exterior of your facility a light colour, if possible. This can help reflect summer heat, ease cooling loads and reduce energy consumption.

• Light-coloured roofing materials not only reduce cooling-energy consumption by 25 to 65 percent during the summer, they also extend roof life.

• “Living” or “green” roofs are becoming more common in Canada. Popular in Europe, these roofs are planted with grass and other vegetation. In addition to excellent insulating properties, this roof style could present multiple uses   and aesthetic appeal   in hotels and restaurants.

The Vocabulary of Building Envelopes

R-values measure the resistance to heat flow that occurs due to temperature differences between the interior and exterior (window and wall) of an envelope. The higher the R-value, the better the insulating properties.

U-values are the inverse of R-values (U = 1/R). In other words, they measure the amount of heat that will move through material rather than resistance to the movement.

Window performance is measured by shading coefficient (SC), solar heat-gain coefficient (SHGC), visible transmittance (T_vis ), luminous efficacy (K_e) and R- or U-values.