Can I build a backyard home in Lake Stevens?
Since 2023, Washington law lets most city lots hold up to two more homes. Lake Stevens writes its own rules on top. Here’s what the code says, in plain English — and a free report on what may fit on your lot.
What Lake Stevens allows.
The headline standards. Open any card for the full wording and the code section.
ADUs per lot2Full wording
2 — 'The installation of two accessory dwelling units (ADU) in any configuration (attached or detached)' (LSMC 14.44.045; city ADU checklist, Apr. 2024)
Max size1,000 sq ft gross floor areaFull wording
1,000 sq ft gross floor area (min. 250) — 'An ADU can be constructed to a maximum size of 1,000 square feet of total gross floor area'; the director may allow more if the ADU fits on one floor within the footprint of the primary unit or an existing legal accessory structure (LSMC 14.44.045(b)(2)–(3))
Max height35 ft (the R4 / WR / R6 zone height)Full wording
No ADU-specific cap in 14.44.045; the zone height applies — 35 ft in R4, WR and R6 (Table 14.48-I). Unpermitted accessory structures are capped at 12 ft (14.48.045(a)(2)), which does not govern a permitted DADU
Front setbackR6 20 ft; R4 and WR 25 ftFull wording
R6 20 ft; R4 and WR 25 ft (Table 14.48-I). ADUs 'shall adhere to the setbacks of the underlying zoning district unless otherwise permitted' in 14.44.045 (LSMC 14.48.045(a)(3))
Side setbackR6: 10 ft total (at least 5 ft one side); R4 / WR: 15 ft totalFull wording
R6: 10 ft total, no less than 5 ft on one side; R4/WR: 15 ft total, no less than 5 ft on one side (Table 14.48-I)
Rear setbackR6 15 ft; R4 / WR 20 ft; none at an alleyFull wording
R6 15 ft; R4 and WR 20 ft (Table 14.48-I). No rear setback for a DADU abutting a public alley (unless routinely plowed); a converted existing accessory structure may stay nonconforming to setbacks and coverage (LSMC 14.44.045(b)(5))
Lot coverageImpervious area: 55% R6, 50% R4, 40% WRFull wording
Regulated as maximum impervious area, not building coverage: R6 55%, R4 50%, WR 40% (Table 14.48-I); infill/middle housing may add 5% (LSMC 14.46.230(c)(3))
Parking1 space (none within ½ mile of major transit)Full wording
1 off-street space per ADU in addition to the principal unit's (Table 14.72-I); none within one-half mile walking distance of a major transit stop unless the city shows it would be significantly less safe (LSMC 14.44.045(c)(1)–(2))
Where a city figure reads stricter than the state floor (RCW 36.70A.681), the floor may control — the report flags it for your parcel.
Living there, selling it, plans, time and fees.
Each answer is the code’s own wording, with the section it comes from. “Not published yet” means the city hasn’t posted a figure — the report asks the city, not the internet.
Are backyard homes allowed?
Yes, attached or detached — 'The installation of two accessory dwelling units (ADU) in any configuration (attached or detached)' (LSMC 14.44.045); ADUs 'P' in R4, WR, R6, R8-12 and MFR, only as accessory to a detached single-family residence (Table 14.40-I fn 6)
Minimum lot size
None for the ADU. Zone minimums for new lots: R6 6,000 sq ft, R4 8,000, WR 9,600 (Table 14.48-I)
Do you have to live there?
No — no owner-occupancy provision in LSMC 14.44.045; city ADU handout (Apr. 2024): 'Property owners are not required to live in the principal unit or ADU.'
Can it be sold on its own?
Yes — 'Individual ADUs can be conveyed separately as condominium units per Chapter 64.34 RCW,' subject to an approved binding site plan under ch. 14.18 (LSMC 14.44.045(b)(4))
Pre-approved plans
None found on the city's permit pages or ADU handout (2026-10-08) — confirm with Planning
How long the city takes
No target published. The city's SB 5290 report for 2024: construction permits averaged 87 calendar days including pauses (55 without), 113 decisions, 25 past the deadline; no single-family/ADU breakout. Completeness review 'typically completed within 3 business days' (Permit Center page)
Impact fees
ADU fee 'shall be no more than 50 percent of the impact fee imposed' on the principal unit (LSMC 14.44.045(b)(9)). Fee Resolution 2025-09 (Oct. 14, 2025): park mitigation single-family $4,572 / ADU 0–1 bedroom $2,104; school (Lake Stevens SD) $13,730 per detached single-family unit, Snohomish SD $5,361; traffic $2,894 (Zone 1) / $3,655 (Zones 2–3) — no explicit ADU traffic/school line, apply the 50% cap. No frontage improvements required (14.44.045(b)(8))
The code is half the answer. Your parcel is the other half.
Lines and easements
Where the lot lines really are, which setbacks apply on each side, and whether a utility or access easement takes the corner you had in mind.
Critical areas and slope
Steep slopes, wetlands and streams come with buffers that no citywide number shows. The report reads the county’s maps for your parcel.
Sewer, septic, water, trees
Whether sewer reaches the lot or it’s on septic, where the water service is, and which trees a city protects — the things that decide where a unit can actually go.
What Lake Stevens allows, what could fit on your lot, and a planning cost range. If something won’t fit, the report says so — and shows what might.
Where this page comes from.
Read from the Lake Stevens municipal code and the city’s own pages on October 9, 2026. The same table feeds the HousUp report, so the report and this page never disagree. Cities amend their codes; before you design anything, confirm the current wording with the city.
- ecode360.com/LA4738
- ecode360.com/48505050 (LSMC 14.44.045)
- ecode360.com/48505776 (Table 14.48-I)
- ecode360.com/48502453 (Table 14.40-I)
- ecode360.com/48507136 (Table 14.72-I)
- lakestevenswa.gov/DocumentCenter/View/13156 (ADU handout, Apr. 2024)
- lakestevenswa.gov/DocumentCenter/View/15517 (Fee Resolution 2025-09)
- lakestevenswa.gov/158
- lakestevenswa.gov/DocumentCenter/View/14341/Staff-Review-Time-for-Land-Use-Applications-2024
- lakestevenswa.gov/380/Current-Planning
- RCW 36.70A.681 — the state floor for accessory dwelling units
Find out what your property could become.
Type your address. Within a few hours: what Lake Stevens allows, what could fit, and a planning cost range. Free, no obligation.