The following rules of measurement shall apply in determining compliance with the requirements of this title. When a required calculation results in a fraction greater than or equal to one-half, the requirement shall be rounded up to the next whole number.

A. Base Density. The “base density” of a property means the density designated on the zoning map, exclusive of any density bonuses.

B. Building Footprint. “Building footprint” is the area at the ground plane of a building, structure, or other element, bounded by the outside of the exterior walls.

C. Building Height. Building height is measured as the vertical distance above “grade” to the highest point of the coping of a flat roof or to the deck line of a mansard roof or to the average height of the highest gable of a pitched or hipped roof. The height of a stepped or terraced building is the maximum height of any segment of the building. The height measurement on an asymmetrical gable shall be the same as a shed roof; it shall be from grade to the midpoint of the longest segment; provided, that the asymmetrical building would not result in a taller building than a traditional symmetrical building. Building height is measured differently in the shoreline jurisdiction.

D. Density. “Density” means the number of dwelling units allowed in the lot area, not including accessory dwelling units. In zones that use floor area ratio (FAR) in place of units per acre, “density” means the maximum floor area allowed.

E. Fence Height. Fence height is measured from finished grade on the exterior side of the fence. Where fences are built on top of berms the maximum height of the fence shall apply to the combined fence and berm.

F. Floor Area. Floor area is measured as the total area of all floors within the exterior vertical walls of a building. If any room has a sloping ceiling, no portion of the room measuring less than five vertical feet from the finished floor to the finished ceiling shall be included in the computation of total area.

G. Floor Area Ratio (FAR). “Floor area ratio” is a figure that expresses the total floor area as a multiple of the lot area. This figure is determined by dividing the floor area of all buildings on a lot by the lot area prior to removal of lot area for dedication. Portions of parking located underground or underneath occupiable space are not counted in floor area ratio calculations. When an historic structure is preserved on site, the floor area ratio of that historic structure shall not be included in the calculation of total floor area ratio for the site. The historic structure must be included on a state, local, or federal register.

H. Front Setbacks. “Front setback” means a setback extending from a building, structure or use to the street or planned right-of-way.

I. Grade. “Grade” (adjacent ground elevation) is the computed average of the lowest and the highest points of elevation of the original surface of the ground, or existing paving or sidewalk within the area between the building and the property line, or when the property line is more than five feet from the building, between the building and a line five feet from the building. On waterfront parcels as defined in the shoreline master program, the definition of average grade level from the shoreline master programs shall be used (WAC 173-27-030(3)).

J. Lot Area. “Lot area” means the total horizontal area within the lot lines, excluding any area seaward of the line of the ordinary high water mark, and excluding private streets and lot area in panhandles or flag lots narrower than 30 feet.

K. Lot Coverage. “Lot coverage” means that portion of the total lot area covered by buildings, excluding up to 24 inches of eaves on each side of the building, any building or portion of building located below predevelopment and finished grade. Any portion of a slatted or solid deck located more than five feet above grade shall be counted towards lot coverage. Also excluded are ground-mounted accessory small wind energy generators, solar panels, composting bins, rain barrels/cisterns, and covers designed to shade ground-mounted heat pumps and air conditioners to increase their efficiency.

L. Lot Depth. “Lot depth” means the horizontal distance from the midpoint of the front lot line to the midpoint of the rear lot line, or to the most distant point on any other lot line where there is no rear lot line.

M. Lot Width. “Lot width” means the diameter of the biggest circle that can fit entirely inside the lot boundary line.

N. Rear Setback. “Rear setback” means a setback extending from a building, structure or use to the rear lot line. If a property has more than one front yard, then rear setback does not apply. In the shoreline jurisdiction, rear setback does not apply since native vegetation zone requirements exceed rear setback requirements.

O. Setback. “Setback” means the required distance measured horizontally between every building, structure or use and the lot lines, planned rights-of-way, rights-of-way or streets.

P. Side Setback. “Side setback” means a setback extending from a building, structure or use to the side lot line. When a parcel has two or more front setbacks, the remaining setbacks are to be considered side setbacks. If a property is bordered on three or more sides by streets, the minimum setback on the remaining side is the minimum setback required for that zone district. If the property is bordered on two sides by streets, the two remaining sides shall meet the minimum and total side setbacks. When a setback for an existing structure is smaller than the minimum required, the minimum for the second side setback does not need to make up the difference – the second side setback need only be as large as if the nonconforming side yard met its minimum requirement.

Q. Structure Height. “Structure height” is measured at the highest point above grade of a structure other than a building, except as otherwise provided by this code.

R. Through Lots – Accessory Building Setbacks. In through lots, setbacks for accessory buildings in rear setbacks shall conform to the front setback requirements for a principal building. Decks less than 36 inches in height extending into required rear and side setbacks may be attached to the principal building. (Ord. 2024-01³ § 1, 2024; Ord. 2022-16 § 1, 2022; Ord. 2021-10 § 3, 2021; Ord. 2020-03 § 3 (Exh. C), 2020; Ord. 2016-28 § 12, 2016; Ord. 2014-04 § 6 (Exh. 4 § 2), 2014: Ord. 2011-02 § 2 (Exh. A), 2011)

Code reviser’s note: The amendments of Ordinance 2021-10 relating to bonus floor area ratio were set to expire one year after adoption of that ordinance. Ordinance 2025-25 extended those amendments to continue in effect until June 10, 2026.

Code reviser’s note: The amendments of Ordinance 2021-10 relating to bonus floor area ratio were set to expire one year after adoption of that ordinance. Ordinance 2025-25 extended those amendments to continue in effect until June 10, 2026.

Code reviser’s note: The amendments of Ordinance 2021-10 relating to bonus floor area ratio were set to expire one year after adoption of that ordinance. Ordinance 2025-25 extended those amendments to continue in effect until June 10, 2026.