Planning Commission to weigh ADU size caps and single-family zone changes for middle housing rules

What the records say

The June 24, 2025 Planning Commission agenda listed an old business item, 'Middle Housing and Accessory Dwelling Units - Additional Policy Questions,' marked 'No action requested at this time; discussion only.' The meeting was scheduled for 6:30 PM at 501 Delta Avenue, Marysville ¹. A staff memo prepared for the meeting laid out seven topics: an ADU size cap (suggested options of 1,200, 1,400, or 1,600 square feet, against the state's 1,000-square-foot-per-ADU allowance under House Bill 1337); whether to amend single-family density rules from 'dwelling units per acre' to 'dwelling units or lots per acre' to accommodate middle housing while preserving existing densities; two options for consolidating the city's four single-family zones (R-8 into R-6.5, or R-8 and WR-R-4-8 into R-6.5, each with an estimated net loss of about 165 units of theoretical capacity); criteria for exempting up to 25 percent of single-family land from middle housing requirements; preserving land capacity in the R-12 and WR-R-6-18 multi-family zones; density levels for master planned senior communities; and whether single-family homes and duplexes in multi-family zones should be allowed up to 35 feet in height ¹. Staff anticipated presenting final regulations in July or potentially August ¹. The May 13 minutes in the same packet note the city must adopt middle housing regulations by June 30 or default to state standards, which staff described as very permissive ¹. These records do not establish what the commission decided at the June 24 meeting ¹.

• The June 24, 2025 meeting was scheduled for 6:30 PM at 501 Delta Avenue, Marysville; item 5.1 was a discussion-only middle housing and ADU policy item with no action requested ¹
• The staff memo proposed ADU size caps of 1,200, 1,400, or 1,600 square feet, noting the state's HB 1337 requires allowing two ADUs per lot at up to 1,000 square feet each ¹
• Two zone consolidation options were presented: fold R-8 into R-6.5, or fold R-8 and WR-R-4-8 into R-6.5; both were estimated to reduce theoretical capacity by about 165 dwelling units ¹
• The memo also sought direction on middle housing exemption areas (up to 25 percent of single-family land), land capacity in R-12 and WR-R-6-18 zones, senior community density, and a possible 35-foot height allowance for single-family homes and duplexes in multi-family zones ¹
• May 13 minutes in the packet record that the city must adopt middle housing regulations by June 30 or default to state standards, and staff planned to present final regulations in July or potentially August ¹

Why it matters

The decisions under discussion shape what can be built on single-family lots in Marysville: how large an accessory dwelling unit can be, how many units a lot may hold, which single-family zones are consolidated, and which neighborhoods may be exempted from state-driven middle housing requirements. Residents in R-8 and WR-R-4-8 zones, in particular, could see zoning changes under the consolidation options. The records show the commission was being asked for policy direction, not final action, and do not establish the meeting's outcome ¹.

What changed / what's next

• The June 24 agenda added a discussion-only item seeking commission direction on seven middle housing and ADU policy questions, with a staff memo detailing proposed size caps, zone consolidation options, and exemption criteria ¹
• These records do not establish the June 24 meeting's outcome or any commission direction given ¹
• Staff anticipated presenting final middle housing and ADU regulations to the commission in July or potentially August ¹
• The available records do not establish the meeting's outcome.