Skylights

When placed correctly, skylights are a dramatic way to bring natural light into your home; transforming close, dark spaces. They can also help tremendously with ventilation. However, they are vulnerable to leaking and heat gain in summer so it is important to choose the correct skylight and make sure your contractor goes the extra mile during installation.

Glazing – You can choose one of two options in glazing for skylights; plastic or glass. Plastic glazing is less prone to breakage, but it scratches and discolors easily and unless the glazing is coated specifically to resist UV radiation, it admits UV light which you want to block. The better skylights use glass glazing that is sealed and insulated. The glass used in skylights is called “safety glass” which refers to both laminated or tempered glass. Both types keep the glass from breaking into large, sharp pieces. For skylights with double glazing, the laminated safety glass is on the interior and the tempered glass is on the exterior. Regardless of which skylight you choose, make sure that it is either tinted, has a low-E coating or an insulated glazing to block UV radiation. The new spectrally selective glazing can cut solar heat gains by as much as 50% compared with clear double glazing.

Controls – Operable skylights that are hard-to-reach or out-of-reach have controls that are either hard wired like your light switches, or controlled by a remote.

Shades and Screens – On South and West facing skylights, in addition to choosing UV blocking glazing, you can also use exterior shades and interior screens to decrease solar heat gain even more. One of the most interesting products on the market is Pella’s Between-the-glass shades that has operable shades between the exterior and interior glass.

Advice – A few well-placed skylights can add beauty and light to your home, but too many can result in glare and overheating problems. One rule of thumb is that the size of the skylight should be between 4-6% of the illuminated floor area.

Splayed light wells provide better light distribution by allowing light to penetrate deeper into the room. Keep west and south facing skylights to a minimum as these create the most problems with solar heat gain and glare. North and east facing lights are the better choice, but keep in mind that east facing windows will heat up a little on summer mornings.