Issaquah, WA Zoning Overlays & Bonuses: Density Bonus Law (2026)

Issaquah's density bonus is the Central Issaquah development bonus program in LUC 18.514.040. Its stated intent is to give developers additional building square footage in exchange for a public benefit of affordable housing, public open space, or both, to create a connected system of open space and urban parks, and to encourage infill and redevelopment within Central Issaquah. Subsection B confines the program to the Central Issaquah subarea, so a parcel elsewhere in the city cannot use it.

A project that opts in still has to meet the standards of its underlying zone, the general affordable housing provisions of IMC 18.514.020, and the affordable housing covenant rules of IMC 18.514.030. That covenant is recorded with the King County Department of Records and Elections before a building permit issues for any development providing affordable housing, and it runs with the land.

The benefit is split by fraction. One-third is the mandatory portion. The other two-thirds is elective, and Table 18.514.040 lists three elective options: the development bonus fee-in-lieu, on-site affordable housing, and public open space. The applicant picks one or more and decides how much of the remaining bonus each option earns. Open space is delivered by providing one additional square foot of on-site open space above the district standard, outside critical areas, for each square foot of bonus, by buying transfer of development rights (TDRs) from authorized sending sites in the City under Chapter 18.806 IMC, or by acquiring TDRs from the Issaquah Creek and Tibbetts Creek watersheds under the City's interlocal agreement with King County.

The fee-in-lieu is available for one whole required affordable unit and for fractions of a required unit that are less than 0.66. At 0.66 or more, the count rounds up to the next whole unit. Subsection G.3 says the dollar amount is set before any building permit issues and is due before any certificate of occupancy, while G.4 requires the fee to be collected before the building permit for the building that benefits from the bonus. Payments go into a dedicated account, the Finance Director keeps the transaction records, the City Council must approve every expenditure, and the City must invest the money within 10 years of payment and inside the subarea where it was collected. Central Issaquah is the priority location for affordable housing funded this way.