DPD Technical Briefs
The following technical information will support projects interested in incorporating solar energy or resources. For additional information, visit www.seattle.gov/light/solar.

Current topics include:

• 
  In 2008, the City of Seattle was one of 25 cities named a Solar America City by the U.S. Department of Energy (DOE).  As a result, Seattle will leverage a $200,000 DOE grant with $200,000 in local funds on a variety of efforts to promote the development of a sustainable solar energy infrastructure. 
• Solar electric systems:  Learn about photovoltaic (solar electric) systems and find code-related information in this DPD Client Assistance Memo (CAM #420). This resource also includes links to valuable technical information on sizing a solar electric system and finding a contractor.
• Solar water heating: One-fifth of a typical Seattle home’s energy budget is spent heating water. Learn how solar hot water systems can help save money on water heating costs, while lessening a home’s impact on the environment, and how federal tax incentives and recent state sales tax exemptions can help shorten their already-quick (often less than 10 years) payback. 
• Sun Chart: Determination of Solar Exposure: The Seattle Energy Code allows credit for passive solar gains through glazing in Group R occupancy (residential) spaces if the Systems Analysis (Chapter 4) compliance option is used. In addition, the Seattle Land Use Code provides certain benefits for solar collectors with good solar exposure. For more information, review Client Assistance Memo 417.

Other Sources of Technical Briefs

• Advanced wall framing: By placing 2x6 studs 24 inches on center rather than the conventional 16 inches uses less wood and allows more room for insulation, increasing the thermal performance of your home. Information provided by Department of Energy's Office of Energy Efficiency and Renewable Energy.
• Airtight drywall approach: Careful sealing of drywall during installation can improve your home's energy efficiency by eliminating air leaks and uncomfortable drafts. Information from the Southface institute in Atlanta, Georgia.
• Pervious paving: Paving alternatives that allow rain to seep into the ground rather than entering the storm water system help retain and restore natural hydrologic cycles and help protect our urban creeks, bays, lakes and Puget Sound. Information from the Puget Sound Action Team.
• Plastic and plastic composite deck lumber:  Recycled-content plastic and plastic composite decking is a nontoxic, low maintenance alternative to wood deck materials. This fact sheet from the Austin, Texas green building program explains the materials.
• Rain gardens: Like pervious paving, rain gardens help keep rainwater on site. They also provide a visual amenity for your yard. This resource is tailored to a Wisconsin audience but is generally applicable. For help with rain gardens in Seattle, contact the Natural Lawn and Garden hotline.
• Rain screen siding (drainage plane): This construction detail helps reduce damage to a home's sheathing and reduces moisture intrusion. Fact sheet from the National Association of Home Builders.
• Tubular skylights: Also called "light tubes," these alternatives to conventional skylights provide natural light to a room with a fraction of the unwanted heat loss and gain. Information from the National Association of Home Builders.

Questions/Suggestions?
If you have questions or suggestions for future technical brief topics, contact our Residential Expert, Sandra.Mallory@seattle.gov.