Buying Guide:Skylights

Skylights can turn a dark, drab living room into a brightly lit area, ideal for hosting guests and spending time with family. They can make a compact bathroom feel larger and more open, just by adding a little light from above. Wherever you choose to install them, skylights can improve energy efficiency, brighten low-light spaces and provide much-needed dimension to a wide variety of rooms. Prior to purchasing a skylight, you'll want to consider what type you need based on where you live and how you plan to utilize it. Keep these questions in mind as you shop: 

• What type of skylight best fits the room(s)?
• What size skylight should you install?
• Do you want an ENERGY STAR qualified model?
• Will a vented or fixed skylight work best?
• Which direction should the unit face? 
  

Energy Efficiency, Materials, Installation Tips and Types 

There are three main types of skylights, ventilating (sometimes called "roof windows"), fixed and tubular. They come in a range of different shapes, including flat, arched, domed and pyramid. Each type has features that make it a good fit for different situations. Choose a design that best fits the room where it will be installed. You should also consider what materials are best and the types of weather it is most likely to be subjected to. In addition to providing extra light that can cut down on lighting costs, how much heat a skylight lets in or out can have a sizable impact on your energy bill.

Energy Efficiency: Your climate can help determine the best location for your skylight. Skylights that face north usually provide steady illumination without absorbing or releasing too much heat. Those that face south will provide extra heat in the winter to reduce heating bills but may retain extra heat in the summer as well. East-facing skylights provide the most light and heat in the mornings while west-facing installations do the same later in the day. ENERGY STAR qualified skylights are available, with ratings based on climate. These units maximize efficiency to lower energy costs. 

• Installation orientation helps determine how much heat and light a skylight receives
• Add a blind or shade to your skylight to reduce undesirable heat during the summer
• Heat-absorbing tints, UV protection and low-emissivity coatings increase energy efficiency and reduce fading in carpeting and furniture
  

Materials: Skylight glazing is generally made from plastic or glass. Plastic glazing, often in the form of acrylics, is more economical and very sturdy, though it can yellow over time and tends to allow more UV rays in, unless it has a special coating. Glass glazing requires a slightly larger initial investment but provides greater durability. In either case, units with insulation tend to hold up longer than single-layer skylights. 

• Plastic glazing is durable and economical
• Glass glazing ensures long-lasting effectiveness
• Solar-heat control glazing adds energy efficiency 
  

Installation Tips: Make sure your skylight is properly installed and fitted to the room to ensure maximum performance. When deciding how big your skylight should be, a good estimate is to have one square foot of skylight for every 20' of floor space. If the room has many windows, the skylight should not be more than 5% of the floor area and, in rooms with few windows, no more than 15%. Condensation can be a drawback, but you can take steps to minimize or eliminate it altogether. Proper installation will reduce the likelihood of condensation, so closely follow installation instructions and consider consulting a professional. Skylights with interior channels collect condensation, preventing drips and allowing condensation to evaporate as temperatures rise. 

• Match skylights to room size for greater light and energy efficiency
• Tightly sealed joints reduce the presence of moisture
• Consistent air circulation decreases the likelihood of condensation buildup
• Skylights may be curb- or flush-mounted, depending on slope and roofing materials
• Flashing may be required for some skylights or roof windows
• Ceiling or exhaust fans built into the wall reduce condensation
  

Light Shafts: Different light shafts provide different looks. Flared shafts are longer than the skylight at the base of the opening to take greater advantage of the sun's path across the sky. Straight shafts are ideal for rooms with little ceiling space or if the roof presents installation obstacles, such as chimneys. Shaftless skylights can be installed into cathedral or high-sloped ceilings to add visual space and create different architectural dynamics. 

• Flared shafts provide a wider beam of light
• Straight shafts work best in flat ceilings
• Shaftless skylights don't need light shafts if ceiling is fastened directly to rafters 
  

Types: Consider the types of skylights available and the rooms in which they will be most effective: 

Skylight Type	Ideal Installation	Points to Consider
Fixed	Any room needing additional light Rooms that do not require additional ventilation	Designed for out-of-reach areas Provides dramatic views Available with durable plastic domes
Tubular	Hallways, pantries, foyers and closets Enclosed spaces	Easy to install Reflective tube is adjustable Fits into tight spaces
Ventilating Skylight or Roof Window	Any room needing additional light Rooms with excess moisture (kitchens, bathrooms, laundry rooms) High or cathedral ceilings Rooms with sloped walls, such as attics or lofts	Ventilating skylights are designed for out-of-reach areas Roof windows are designed for in-reach areas Select manual or electric operation Open to provide extra ventilation Easy to clean

Features 

Motorized Venting Skylights: Motorized units eliminate the hassle of having to manually crank open hard-to-reach skylights and let you add a breath of fresh air with the touch of a button.

Moisture Sensors: Vented skylights with moisture sensors close automatically when it starts to rain, ensuring that the room below stays dry even if you're not home to close the skylight.

Flashing Kits: These kits interweave with roofing materials to ensure proper drainage and reduce condensation, protecting furniture below.