ADU Permits: Bellevue vs Kent
How do adu permits rules compare between Bellevue, WA and Kent, WA?
Bellevue and Kent have similar restriction levels.
Bellevue, WA
King County
Bellevue permits accessory dwelling units under Land Use Code (LUC) 20.20.120, substantially amended by Ordinance 6746 (2023 ADU Reform LUCA). Washington HB 1337 (RCW 36.70A.681) requires Bellevue to allow up to two ADUs per lot in urban growth areas, and the city's middle-housing LUCA is being adopted to comply by the June 30, 2025 statewide deadline.
View full Bellevue rules →Kent, WA
King County
Kent permits accessory dwelling units under KCC 15.08.250, updated June 2023 to implement Washington HB 1337 (RCW 36.70A.681). Up to two ADUs are allowed per single-family lot, each up to 1,000 square feet and 24 feet tall. Building permits are filed through the Kent Permit Center using the regional MyBuildingPermit.com portal.
View full Kent rules →Key Facts Comparison
| Fact | Bellevue | Kent |
|---|---|---|
| Code Section | LUC 20.20.120 | KCC 15.08.250 |
| Reform Ordinance | No. 6746 (2023) | - |
| Max Size | 1,200 sq ft or 40% of structure | - |
| State Law | HB 1337 / RCW 36.70A.681 | RCW 36.70A.681 |
| ADUs Per Lot | Up to 2 (state-mandated) | Up to 2 (per HB 1337) |
| Permit Portal | MyBuildingPermit.com | MyBuildingPermit.com |
| Max Size Each | - | 1,000 sq ft |
| Max Height | - | 24 feet |
Highlighted rows indicate differences between cities.
Bellevue FAQ
Do I need a permit to build an ADU in Bellevue?
Yes. A building permit is required, filed through MyBuildingPermit.com, and a final land-use planner inspection is required before occupancy. Registration and public noticing were removed by Ordinance 6746 (2023), but the construction permit itself remains mandatory.
How big can my ADU be in Bellevue?
LUC 20.20.120 allows an ADU up to 1,200 square feet or 40 percent of the primary structure, whichever is larger. Attached ADUs must comply with the same height and setback rules as the primary residence.
Kent FAQ
Do I need a permit to build an ADU in Kent?
Yes. A building permit is required through the Kent Permit Center, filed via MyBuildingPermit.com. The ADU must meet KCC 15.08.250 standards and the 2021 I-Codes as adopted by Washington. Electrical work requires a separate Washington L&I permit, and final inspection sign-off is required before occupancy.
How many ADUs can I build on my Kent lot?
Up to two ADUs per single-family lot under KCC 15.08.250, consistent with Washington HB 1337 (RCW 36.70A.681). They may be two attached units, two detached units, or one of each, and each is capped at 1,000 square feet and 24 feet in height.
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