Showing ordinances that apply to Lake Holm, WA
Lake Holm is an unincorporated community (population 3,430) in King County, Washington. Because Lake Holm is not an incorporated city, it does not have its own municipal code. Instead, King County ordinances apply directly to properties here. The adu rules rules below are the ones that govern your area.
Unincorporated King County allows up to 2 ADUs on single-family lots under WA HB 1337 (2023): one attached and one detached (DADU). No owner-occupancy requirement; parking waived near transit.
Washington House Bill 1337 (2023, codified in RCW 36.70A.681) mandates that cities and counties planning under the Growth Management Act allow up to two ADUs per single-family lot in urban growth areas. King County has updated KCC Title 21A to comply: on most urban residential lots (R and UR zones), an owner may build both an attached or interior ADU and a detached ADU (DADU) simultaneously. Maximum DADU size is generally 1,000 square feet or the state-mandated 1,000 square feet minimum, and height is up to 24 feet (or greater with a variance). Owner-occupancy cannot be required. Off-street parking cannot be mandated within a half-mile of a major transit stop. ADUs must meet International Residential Code standards, King County septic or sewer rules (Public Health Seattle and King County oversees onsite septic under WAC 246-272A), and critical-area setbacks under KCC 21A.24. Rural Area (RA) parcels can build one DADU under traditional rural zoning, not the full HB 1337 two-ADU rule, which applies in urban growth areas. Condo or townhouse conversion of ADUs is allowed. Short-term rental of ADUs may be restricted where local transient accommodation rules apply.
ADU without permit: stop-work plus double fees. Violating size or height: correction or removal. Failed septic expansion: public health abatement.
See how Lake Holm's adu rules rules stack up against other locations.
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