To install dormer window kits, first plan where the window belongs compared to the type of dormer it is. Measure the dormer and the area in which it is to be placed. Remove each layer of the roofing from the area, and cut the support beams according to the dormer kit plans. Attach the beams to the frame of the roof. Place the vertical face of the dormer parallel to the house, and secure the sides of the dormer.
Completely attach the frame to the roof, and check that the frame supports the weight of the window. Install the layers of the roof, such as weatherproofing materials, plywood, shingles and siding, around the opening. Place the window into the frame. Install the insulation and drywall inside the home, and prime it to paint once it dries.
When choosing a style of dormer kit, consider the kind of supplies needed to install it, or where on the house you wish to install it. Install a shed dormer on the back or side of a house because it has a higher chance of leaking when placed elsewhere. Blind dormers are easy to install but need to be secured properly and painted so they blend in to the exterior. Gable-fronted dormers require more extra roofing supplies than others.
Some materials needed outside of the kit are beams for rafters or support, a level to ensure an even install, and a tape measure to cut to exact specifications. For beams that need to be cut, use a table saw that cuts non-right angles. Ensure you have the proper screws, bolts and replacement roofing, insulation and drywall materials.