Skylights are not very expensive to purchase; the installation forms the bulk of the purchase. It may be recommended that a licensed contractor fits the skylight, though it can even be even done yourself if you are good with your hands and have done such mechanical jobs before. If you chose to get it done through a contractor, its best always to research a few companies to find the best rates and service. Recommendations from friends are a smart way to take a decision.

Most installations involve just three easy steps. First, you need to determine the location and cut an opening into the roof and the ceiling. Then, the skylight unit has to be attached to the roof, making sure all joints are sealed. And lastly, the light shaft from the roof to the ceiling has to be made with drywall or paneling.

Complex skylight shafts, however, can take a lot of time to construct. Structural work may have to be done or roof-framing members may need to be altered to create the light tunnel. This cannot be attempted at home even if you consider yourself very skilled. It’s best in such cases to get help from a professional installation agency. Most manufacturers offer installation service.

While installing skylights, you must keep in mind that even the most energy-efficient skylights have to be very carefully installed to ensure that the maximum energy performance is achieved. This is the reason that it is advised to have a professional install your skylight.

In addition to carefully following the manufacturer's guidelines when installing a skylight, it's also most important to consider slope and moisture control. The slope is the tilt of the skylight, and it greatly affects solar heat gain. A low slope will admit relatively more solar heat in the summer and less in the winter; exactly the opposite of what is required in your house. You should keep in mind that the recommended slope should be equal to your geographical latitude, plus five to fifteen degrees.

Another important factor to be kept in mind at the time of installation is that water leaks are a common problem with skylights. In order to avoid leakage, you should ensure that the skylight is mounted above the surface of the roof and that a curb is installed. A curb is a raised, watertight grip that deflects the rainwater. You should also ensure that all joints are permanently sealed.

Finally, it is wise to apply a layer of sheet waterproofing over the curb as an aid to protect against water clogging or leakage.