Issaquah, WA Building Setbacks & Zoning: Structure Height Limits (2026)

Land Use Code § 18.404.050 states its purpose as balancing lot size, building bulk and open space, and ensuring that architectural character and scale are compatible with the surrounding area. In nonshoreline areas, height is measured from the average grade of the existing or finished grade, whichever is lower, to the midpoint of the highest gable of a pitched or hipped roof with a minimum 4:12 pitch and a maximum of 12:12 pitch, or to the highest point of the coping of a flat roof. All parts of the roof extending above the base building height must be at least 4:12 pitch unless an exemption applies. Gabled dormers can make up no more than 50 percent of the total roof area in plan view, no portion of a shed roof can extend above the base building height limit, and an architectural feature cannot be used to measure or establish building height. In shoreline areas, height is measured from the average of the existing topography of the portion of the lot under the building or structure.

Average grade comes from an accurate scaled drawing of the footprint showing existing and proposed topography with contour lines at two-foot intervals. Spot elevations are taken at points every 10 feet around the footprint, using the lower of existing or proposed, and the elevations are added up and divided by the number of points.

Certain features are not subject to height limitations and need no deviation, provided they are architecturally integrated: water towers, power transmission towers, chimneys and smoke stacks to the minimum required by the Building Code, flag poles within the limits of Chapter 18.612 IMC, scenery lofts and flytowers, mechanical penthouses, rooftop equipment screening and stair towers to the Building Code minimum, elevator shafts to the minimum required by IMC Title 16, and solar panels or arrays per IMC 18.602.060. Wireless communication towers follow Chapter 18.512 IMC, except towers regulated in residential zoning districts.

The base and maximum height for each residential zone are set in Table 18.404.090(A), Residential Zones Form and Intensity Standards. Section 18.404.060 allows more height on parcels outside Central Issaquah, Issaquah Highlands and Talus, including Multifamily-Medium and Multifamily-High parcels. Up to 50 feet through a Director's deviation requires stepbacks that reduce the gross floor area of each added story by 25 percent of the story beneath it, a 10 percent increase in pervious surface, and, next to a lower-density residential zone, the lower zone's maximum base height for the first 30 feet from the property line. Up to 65 feet adds clusters of trees around the buildings and an approved site development permit. Neither tier can exceed the maximum building height in Table 18.404.100(B).