Skylights allow natural light to enter a home.
A skylight is a special type of window built into the roof of a house to let natural light directly into the house. A skylight can be installed for aesthetic purposes or as part of an overall passive heating strategy. There are many different types of skylights, with different designs, materials and additional components.
Many people end up choosing a skylight that is too big for their home in order to try and add as much light as possible. Unfortunately, even the best skylights have much poorer insulation than a comparable roof space, so a large skylight allows large amounts of heat to escape during cold weather and a lot of heat to enter the home during hot weather. For this reason, it is recommended to consider how much direct sun the roof receives and how big the temperature change is from one season to the next, before choosing a skylight. In general, a skylight allows approximately eight times as much light to enter the home as a comparable sized wall window.
The purchase and installation of a basic skylight costs approximately $1,000 to $2,000.
There are three main classes of widely used skylights. A ventilation skylight can be opened to allow air to pass through. These skylights are ideal for bathrooms and kitchens, where they help relieve excess moisture and keep the airflow constant. Ventilation skylights can be controlled by a remote control, by a crank or by an automatic sensor that monitors the internal temperature.
A fixed skylight is any type of skylight that does not open. This type of skylight is exclusively intended to allow light to enter the house. Lastly, the tubular skylight is essentially a very small skylight, primarily intended for hallways and small rooms where a traditional skylight would not easily fit.
There are nine main skylight styles in use, which can be used for both ventilated and fixed skylights. Five of these are relatively common in small to medium-sized homes, with the cost and difficulty of installation largely depending on the style chosen.
A flat skylight is probably the most common, consisting of a square or rectangular piece of flat glass or acrylic, which can be fixed or ventilated. A round skylight emerges from the roof like a half-sphere bubble. A polygonal skylight rises from the roof with a series of glass or acrylic polygons – these skylights are considerably more expensive than the simpler models, but they are also very aesthetically impressive. A pyramidal skylight is a simple pyramid of four triangles that protrudes from the roof. Finally, a domed skylight is similar to a flat skylight, except the rounded glass passes through the roof surface.
In addition to these primary residential styles, there are four skylight styles most often associated with large buildings. The hip crest skylight is a long rectangular skylight that peaks above the roof surface to a central ridge, with a slanted triangular piece of glass at each short end. The summit skylight is a simpler version, with two long triangles angled towards each other and right triangles closing at either end. The sloping skylight is a simple slope that rises from the roof of one floor and ends against an upper wall of the next floor. The barrel vaulted skylight is a more complex form of porch consisting of a half-sphere against an upper wall, often seen in large arboretums.
The two main materials used to build a skylight are glass and acrylic. Both have their strengths and weaknesses, and it is often a simple matter of preference. Both have different glasses available, different insulating factors, and a slightly different appearance to the trained eye. Some other synthetic materials are also occasionally used, particularly Lexan, which has the added benefit of high durability and is recommended for regions that experience heavy storms.
The glazing, insulation factor and durability of a skylight are additional factors to consider when purchasing a skylight. Glass skylights can be purchased with multiple panels, with the area between the panels serving as an insulating region. All skylights can be glazed to protect against ultraviolet radiation, to reduce the amount of light that can pass through, or to increase the amount of heat trapped. Buying and installing a basic skylight costs approximately $1000-$2000, with more durable and more technologically advanced models rising in price quickly. Ornate shapes and spikes also add significantly to the cost, while installing multiple modules often reduces the cost per unit noticeably.