I want to build a deck off my family room’s sliding glass door. I want it to be as environmentally friendly and energy efficient as possible. What suggestions can you give me?—Robert C.
Adding a deck to a house, especially if you do most of the work, can increase the home’s resale value by more than the deck’s cost. Since you are building it by an existing sliding glass door, there are probably some concrete steps or landing, providing a stable base near the house. You should always attach a strong ledger board to the house wall framing or masonry.
A deck can be energy efficient in several ways. If having a deck allows your family to spend more time outdoors during summer, then you should be able to set your central air conditioner’s thermostat higher during the time you’re primarily outside.
If you are outdoors more often, you will become accustomed to the heat and will be more comfortable indoors without as much air conditioning.
A properly designed deck with a pergola or some type of tall side wall facing south or southwest can also provide shade for your home. This is particularly helpful if it can also shade the glass patio door.
Options for deck materials
Environmentally friendly choices are available for deck materials. For the framing, engineered lumber made for exteriors can be used instead of standard solid lumber. Engineered lumber is stronger and often made from smaller wood pieces so less prime wood is required overall.
The choice of deck material is most important. Pressure-treated wood is abundant and the least expensive material you can use. Wood also has a nice appearance and feel on bare feet and is easy to work with. Some environmental drawbacks to wood are its limited life and the cleaning and sealing chemicals that must be applied every year or two to extend its life.
Composite decking is another option. Trex recently developed a decking material, Transcend, which is made from at least 95 percent recycled materials.
Another option is cellular PVC decking. It uses more virgin materials than composites, but it is durable, low-maintenance, and highly resistant to stain or mildew.
Making shade for your deck
Building a vertical wall on the southwest side of the deck fosters effective shading and also provides privacy. The simplest design uses standard posts covered by lattice. The lattice openings let breezes pass through. Planting climbing vines along the lattice also enhances the cooling effect.
To block the sun from overhead direction, build a garden feature called a pergola over the deck. By allowing climbing vines to grow up and over it, the pergola creates additional shading.