Skylights are fantastic at bringing natural light into your home, but they penetrate a part of the building envelope which is important to be as airtight and thermally consistent as possible. Like windows, skylights can affect energy efficiency, indoor comfort but additionally they can:
- Can leak water, causing damage to your building.
- Build up with dead insects.
Skylights transfer heat energy very efficiently. On a hot day,
- Solar heat from the sun is transmitted straight through a glass/old plastic skylight,
- A hot roof area also radiates straight through the un-insulated walls of the skylight,
Warming the interior of the building and adding to the cooling load that is required to keep the building temperature at a comfortable level. During colder weather, the heat inside the house rises and radiates/leaks through the glass/skylight design into the outdoors, and your ducted heating or split system runs longer and harder to compensate, increasing energy use. The heat loss in skylights is more significant with a skylight than a facade window in a building because the heat in a room naturally rises and accumulates at the ceiling. As an example to understand this, in Australia, double story homes always get hotter upstairs in summer than the downstairs area.
Here are some quick and not so quick tips to get around the issues above so that skylights can still benefit your building.
- When installing from scratch – Think about direction and exposure. A skylight installed in the south of a pitched roof gets more light than heat during most of the day. An east pitched skylight receives morning light and heat, while West pitched skylights get more heat and light in the afternoon. Heat gain issues can be reduced by shading the roof with deciduous trees that shed their leaves in winter or by utilizing window roller shutters that can be manually closed or opened at peak hours of solar exposure depending on the climate.
- When buying new – Think very seriously about energy-efficient glass options. Similar to windows, skylights today offer glazing that reduces heat transfer in and out of the house while still providing acceptable levels of visible light and a clear view of the great outdoors. Some skylights have glass composed of “sandwiched” layers of glass incorporating argon gas between the layers to reduce heat transfer. Low-e glass is also available to diminish heat gain and loss. Also, think about size, the smaller the skylight, the better. The smaller units still produce excellent light output.
When Retrofitting. Insulate the skylight walls, and install some Suntuf see through 8mm cor-flute plastic, in line with your plaster building envelope, to give you a better R-value in between your living area and your skylight temperature.
- Remove your skylight altogether.
Send us an email if you need more information regarding the retrofit.