Setback

Key Takeaways

• A setback is the minimum distance a structure must sit from a property line, measured to the front, side, or rear line.
• Setbacks come from local zoning ordinances rather than a statewide rule, so the distance changes from city to city and from zone to zone.
• RCW 35A.63.100 lists setbacks among the standards a code city may impose through its zoning ordinance.
• An owner who cannot meet a setback applies to the local board of adjustment for a variance, which is granted only on findings of special circumstances.

What It Means

A setback is the minimum distance a local zoning ordinance requires between a structure and a property line. Most codes set three of them: a front setback measured from the street line, side setbacks, and a rear setback. The strip of land inside the setback is a required yard and has to stay open, so the house, the garage, and any covered addition must sit outside it.

Setbacks are an exercise of the Police Power, the government's authority to regulate the use of private property for public health, safety, and welfare. They keep light and air between buildings, give fire crews room to work, protect sight lines at corners, and hold a consistent street edge. Where a buffer zone protects a stream, a wetland, or a steep slope, no building or activity is allowed inside the buffer at all, and the zoning setback is often still measured from the edge of that buffer rather than from the property line.

For a buyer, the setback decides what can be built and where an addition can go. For a seller, a structure that already sits inside a setback is a permitting problem, and a Survey is usually what brings it to light.

How It Works in Washington

Washington sets no statewide setback distance. The numbers live in each city's or county's Zoning code. RCW 35A.63.100(2)(a)(i) is the enabling language for code cities: after the comprehensive plan is adopted, the legislative body may divide the municipality into zones with standards for the use of land and buildings, the location, height, bulk, number of stories, and size of buildings, the size of yards, courts, and open spaces, and setbacks. Cities and counties working under the older planning act have the same reach: RCW 35.63.080(1)(a) lets the council or board regulate the size of yards, courts, and other open spaces on the lot, and the setback of buildings along highways, parks, or public water frontages.

When a lot cannot meet the setback, the owner asks for a variance. Under RCW 35A.63.110(2), a board of adjustment may grant one only if it finds that the variance is not a grant of special privilege inconsistent with the limits on other property in the same zone, that it is necessary because of special circumstances of the size, shape, topography, location, or surroundings of the property, and that it will not be materially detrimental to the public welfare or injurious to nearby property.

Washington's middle housing law reaches setbacks as well. RCW 36.70A.635(6)(b) bars a covered city from applying development standards to middle housing that are more restrictive than the standards it applies to detached single-family residences, and it names set-back requirements as one of the standards a city may apply only on that equal footing.

Example

Owen owns a 7,200 square foot lot that measures 60 feet wide by 120 feet deep. The zoning code for his neighborhood requires a 20 foot front setback, 5 foot side setbacks, and a 20 foot rear setback, which leaves a buildable envelope 50 feet wide and 80 feet deep.

Owen wants to add a 24 foot deep family room to the back of a house that already stands 30 feet from the rear property line. The addition would leave 6 feet of rear yard, well inside the 20 foot rear setback, so the city denies the permit. Owen applies to the board of adjustment for a variance and argues that a drainage easement running along one side of the lot makes any other location impossible. The board is looking for special circumstances of the lot, not for the fact that Owen wants a larger house, so the easement is the part of his argument that carries weight.

Common Mistakes and Exam Traps

• A setback is measured from the property line, not from the curb, the street pavement, or the sidewalk.
• A variance excuses a dimensional requirement such as a setback. A conditional use permit allows a listed use that requires review before it can locate in the zone. Exam questions swap the two.
• A building that met the setback when it was built and no longer meets a changed rule is a nonconforming structure, which is a different answer from a zoning violation.
• Under RCW 36.70A.635, a city covered by the middle housing law cannot impose setbacks on middle housing that are more restrictive than the setbacks it imposes on detached single-family residences.