Doors include exterior entry doors and interior passage doors. They come in a wide range of styles and materials such as wood, wood composites, fiberglass, vinyl and metal. From a green standpoint, look for doors that are durable and made from materials that don’t have a negative effect on the human or natural environment.
For exterior doors, weather tightness, insulating value and leak free installation is important. Ornamental entry doors are usually more about looks than energy efficiency. A solid core wood door is about R-1 per inch of thickness. They have about the same insulating value as an average double glazed window, but with more potential to leak air. With a storm door, the efficiency is about R-3, which doesn’t compare to an R-24 exterior wall assembly. Insulated fiberglass or steel doors are several times more energy efficient than a solid wood door. Fiberglass is more impact resistant and conducts less heat than a metal faced door, and fiberglass can look very much like a wood door. If going with a solid wood door, look for wood that is reclaimed or sustainably harvested. Sliding glass doors are basically windows that are large enough to walk through. The same considerations for choosing and installing windows apply. Special consideration needs to be given to the sill by providing a sill pan to isolate the subfloor from water.
For interior doors, there are many styles and materials to choose from, such as solid wood to hollow core panel. Medium density fiberboard (MDF) is an alternative to solid wood. It is a solid, engineered product made of the residual fibers from the production of large wood products. It thus makes use of material that would otherwise be discarded. When considering the environment, look for wood from sustainable sources and harvesting techniques. A problem which has occurred in the harvesting of exotic hardwoods is the importing of these woods from unknown sources. Often this results in the case of clear cutting the rain forests with subsequent damage to the environment. From an indoor air quality standpoint, it is best to avoid doors that use urea formaldehyde adhesives or binders to hold the door structure together.
The exterior door for our subject house will be insulated fiberglass with a wood grain texture and a stained finish. The space between rough opening and frame will be sealed with polyurethane foam and the exterior with self adhering flashing and sealant. The door will be set on sill pan flashing. Interior doors will be MDF with a painted finish.