Operable Skylights

We hear about all sorts of exotic and futuristic ways to save energy. But we hear very little about some simple, proven and cost effective methods: operable skylights.

Operable skylights can help reduce cooling costs in most climates. Once installed they require very little energy and almost no maintenance.

I have two small Velux Skylights in my home. That are over 20 years old. They work like a charm and keep our home cool during the summer.

No magic! Just a bit of planing and some good quality operable skylights. - George


  • Good quality operable skylights are one of the best ways to keep homes cool. They allow warm air to escape from high ceiling locations and that in turn pulls cooler air from shaded and cool areas into the house. Such convection action works like a fan but better.

    Operable Skylights do not:

    • require a motor to move the air - some use a small motor to open and close the skylight,
    • use electricity to move the air, or
    • make noise,

    They can add light to a dark area of the house, and most homes can be retrofitted with an operable skylight for less cost than an air conditioning unit for a single room.

    I have them in my home. I use them all the time. I love them and I love to recommend them to people whose homes need cooling systems.

    Velux ... and help keep your home cool!

  • Here are a few tips:

    • The best location for operable skylights is on the side of the house opposite of the prevailing winds. This helps draw air out of the house. For example, in the Puget Sound area the best location would be on the east or north sides of the house.
    • If the house has two floors and an open staircase then a centrally located skylight in the 2nd floor hallway will work very well.
    • A single story house may require more than one operable skylight because it may not have the vertical space (height) to create a good convection current.
    • Most operable skylights are designed not to allow for rain entry when left partially open. We have an operable skylight at our cabin and leave it partially open from May till October - no problem.
    • An operable skylight in a bathroom can double as a moisture venting system.
    • The size of the skylight is not as important as its location.
    • The best time to add an operable a skylight is when new roofing is installed or when the roofing material is relatively new and flexible.
    • Some manufacturers of operable skylights provide optional shading and screening systems.
    • Some skylight models open and close with small motors and can be programed with thermostats, rain detectors and all sorts of fancy equipment. (I prefer a long pole or crank.) But motorized and automatically controlled units can make a lot of sense, for example in hard to reach locations.

  • Operable skylights can also save energy in homes with mechanical air conditioning. They can be used to keep the home cool and comfortable during shoulder seasons. Operable skylights and other passive cooling methods may not be adequate to cool a home in hot climates but they can be used to reduce energy consumption in all climates.

    Passive cooling methods have been used all over the world for centuries to keep homes cooler. Today's quality skylights make that task easier.

    and a note from a satisfied customer...

    George -

    Thank you so much for the suggestion of installing an operable skylights in our town home. They have absolutely saved us through the hot summer with the increased ventilation. With our tower of a house it really helps regulate the temperature. We end up having the bathroom skylight open almost all the time.

    Thanks again for all the great advice! Shannon H

    As any good cooling or heating system, the use of operable skylights to cool a home does require some design and planning. But when properly designed and installed, operable skylights can help keep your home cooler and save you a substantial amount of energy. - George