Island County, WA Zoning Overlays & Bonuses: Density Bonus Law (2026)
Key Facts
- Rural 20-40 acre bonus
- 100% density, 65% open space
- Rural 40-80 acre bonus
- 125% density, 80% open space
- UGA PRD bonus
- 200% density, 75% open space
- Rural Forest 20-80 acre bonus
- 100% density, 85% open space
- RA/CA standard PRD bonus
- No bonus, 50% open space
- Approval mechanism
- PRD under chapter 16.17
Summary
Island County's density bonus system (Island County Code section 17.03.180.E) rewards cluster development that preserves open space, critical areas and farm or forest land. Parcels of 20 to 40 acres in the Rural Zone can earn a 100 percent density bonus by dedicating 65 percent open space; 40 to 80 acres can earn 125 percent with 80 percent open space, all through a Planned Residential Development (PRD).
E.Density bonus system.1.The density bonus system is designed to provide incentives for cluster development in order to:a.Reserve opportunities for future urban development;b.Provide permanent preservation of open space, critical areas, wildlife habitat and natural lands; andc.Protect agricultural and forest resource lands.2.Bonus densities are as follows: Zone Maximum Density Bonus Minimum Open Space Ratio ... Rural ... AG, Commercial AG Standard PRD Bonus None 50%
Full Breakdown
" In the Rural Zone, parcels under 20 acres and over 80 acres earn no bonus and must set aside 30 percent open space; parcels of 20 to 40 acres can earn a 100 percent density bonus with 65 percent minimum open space, and parcels of 40 to 80 acres can earn 125 percent with 80 percent open space. A PRD inside an urban growth area can earn a 200 percent bonus with 75 percent open space treated as urban reserve. Rural Forest parcels of 20 to 80 acres can earn a 100 percent bonus with 85 percent open space.
In the Rural Agriculture and Commercial Agriculture zones the standard PRD bonus is capped at zero additional density, but 50 percent open space is still required. The bonus itself is calculated by dividing the open-space acreage by the base-density acreage and multiplying by the permitted bonus percentage; the result is added to base density to produce the allowed unit count, rounded upward for fractional units. 17, and the Director or Hearing Examiner can require clusters to be sited away from critical areas or RA, RF, CA and AP lands, or can widen buffers around them.
Violations & Fines
Building above the density allowed for a parcel's acreage tier, or claiming a bonus without an approved Planned Residential Development under chapter 16.17, is a zoning violation that Planning and Community Development will catch at plat or building permit review. Clustering units without recording the required open-space ratio, or siting clusters inside critical areas the Director or Hearing Examiner ordered avoided, can result in permit denial, a stop-work order, or a requirement to re-plat before further building permits issue.
Frequently Asked Questions
How much density bonus can a Rural-zoned parcel earn in Island County?
Can a parcel inside an urban growth area get a bigger bonus?
Do Commercial Agriculture parcels get a density bonus?
How is the bonus density calculated?
Sources & Official References
Other rules in Island County
Compare Island County to another location·View the Washington zoning overlays & bonuses overview
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