There are a number of elements that influence how effective a skylight can be. One of the most important elements is the configuration of the roof. That is how the roof is framed (stick or truss), its pitch (the rise to run ratio), and the style of the roof (gable, hip, etc.). For example, you may wish to install a skylight in your bathroom where no window exists. Upon further investigation you may find that a valley (the low point of the roof at which two planes meet to create a trough) exists which make it virtually impossible to install a skylight in that location. The same is true where a proposed skylight may come into play with a hip or the ridge of the roof. There is an exception however where the roofs ridge is concerned. Many major manufacturers of skylights produce a "ridge skylight" which is designed especially for installation at the ridge.

Another example would be the installation of a skylight in a high-pitched roof. More often then not this would necessitate the construction of a long tunnel-like chase which commences at the ceiling and terminates at the roof. Although you would gain some light you may find that it is significantly less then what you expected due to the long chase. This condition is especially true at interior halls at the center of the home where the roof is often the highest.

If you live in a home where the roof framing system consists of manufactured trusses the size and shape of your skylight is typically dictated by the configuration of the trusses. This is due to the fact that most building officials will not allow existing roof trusses to be cut or altered without very specific engineering. This could tend to make what started out to be a simple skylight installation a very costly undertaking.

Finally, be conscious of exposure when considering the placement of a skylight. That is to say that a skylight may sound like a terrific solution to that dark kitchen until you discover that it faces South. You may be trading dark space for very hot space. All things considered if the only place for the proposed skylight is on the "hot" side of the house then we suggest that you take a good look at the energy efficient units that are available that are insulated, gas filled, tinted, and even ventilating. These features will significantly diminish the amount of heat allowed into your home.

Oh yes, and most important of all, that houseplant that has been suffering in your dark bathroom will love you forever.