ZONING

Residential, single family zoning provides an area for single family dwellings and townhouses at urban densities, plus other related uses, which contribute to a complete urban residential environment. These other uses which include churches, schools, libraries and other neighborhood buildings are compatible with single family, residential use.

Building and zoning codes regulate the location, size, and lot coverage of single family homes in the Puget Sound area. The general discussion of lot coverage, height and yard are presented as a general guideline. Rural residential zones can vary widely because of water and sewer restrictions.

Homes and other associated structures may cover 35% of the lot (40% in some areas). When calculating lot coverage you must include balconies, bay windows and architectural projections (such as eaves and gutters over 18 inches wide, even though they do not actually touch the ground.)

Certain structures are not counted in lot coverage. These include: uncovered decks, pools of 18 inches or less in height, access structures for the disabled, pedestrian bridges (5 feet wide or less) needed for access from a street, alley or easement, underground structures and bulkheads and solar collectors that meet certain standards.

In general, your home must not exceed 30 feet in height above existing grade on any portion of your lot. If you are planning to build a home between two single family structures, one or both of which exceeds 30 feet, you may use the average height of the two adjacent structures as the height limit, so long as that does not exceed 40 feet.

If you have a pitched roof, the ridge of the roof may exceed 5 feet above the height limit if the pitch of the roof is at least 3 to 12 feet.

If you wish to build a home on a sloping lot, you may be eligible to have additional wall height along the lowest elevation of the site. Basically, you may be allowed one foot of height in addition to the 30-foot limit for each 6 percent slope of the existent grade of the site.

Land Use Codes require that certain portions of your lot be set aside for front, rear and side yards. In general, no portion of your house may extend into these required yards. You may place accessory structures such as garages, sheds, decks and porches in these yards only if certain criteria are met. Of course, you may provide more than the required minimum yard. The standard yard requirements are:

Front Yard: 20 feet, or the average of the front yards of the single-family residences on either side of your lot, whichever is less.

Rear Yard: 25 feet

Side Yard: 5 feet

The Seattle Department of Construction and Land Development has more through information.

Check King County for more detailed information.