Can I build a backyard home in Medina?
Since 2023, Washington law lets most city lots hold up to two more homes. Medina 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 Medina allows.
The headline standards. Tap any one for the full wording and the code section.
ADUs per lot2Full wording
2 — 'A maximum of two accessory dwelling units may be permitted on a lot per each single-family dwelling' (MMC 16.34.020(C)); density is 2 units per lot, 'except if one unit is a single-family dwelling unit, then up to two accessory dwelling units ... may be allowed'; no ADUs on a lot with two middle-housing units such as a duplex (MMC 16.21.060(A), Ord. 1040)
Max size1,000 sq ftFull wording
1,000 sq ft — 'The maximum gross floor area for an accessory dwelling unit is 1,000 square feet.' (MMC 16.34.020(D)(8), Ord. 1040); the old 'lesser of 1,000 sq ft or 40%' rule was deleted
Max height25 ftFull wording
25 ft — 'The maximum roof height for an accessory dwelling unit is no more than twenty-five (25) feet, or the maximum height allowed for the primary unit on the lot, whichever is lower.' (MMC 16.34.020(D)(9)); R-16 primary limit is 25 ft above original grade / 28 ft above finished grade (MMC Table 16.23.050(A))
Front setback30 ft on lots of 15,001 sq ft and upFull wording
30 ft on lots of 15,001 sq ft and up (typical R-16/R-20); set by lot area, not zone: 25 ft under 10,001 sq ft, 26 ft for 10,001–13,000, 28 ft for 13,001–15,000 (MMC Table 16.22.030). ADUs follow the zone's setbacks (16.34.020(D)(1))
Side setback15 ft on lots up to 20,000 sq ftFull wording
15 ft on lots up to 20,000 sq ft; over 20,000 sq ft, the greater of 15 ft or 20% of lot width, max 20 ft (MMC Table 16.22.030 as amended by Ord. 1062, effective Oct 20, 2026)
Rear setback30 ft on lots of 15,001 sq ft and upFull wording
30 ft on lots of 15,001 sq ft and up; 25 ft under 10,001, 26 ft for 10,001–13,000, 28 ft for 13,001–15,000 (MMC Table 16.22.030). 'Detached ADUs may be sited at a lot line if the lot line abuts a public alley, unless it is a public alley that the City regularly snow plows' (16.34.020(D)(10))
Lot coverage25% structural coverage on a 16,000 sq ft R-16 lotFull wording
25% structural coverage on a 16,000 sq ft R-16 lot — a sliding scale from 30% at 10,000 sq ft or less to 21% at 19,501 sq ft and up; impervious surface 55% (MMC Table 16.23.020(A)). R-20/R-30/SR-30: 25% down to 21%; impervious 52.5% (50% for R-30/SR-30 lots of 30,000 sq ft and up) (Table 16.23.020(B))
Parking1 per ADU, on top of the house’s; none within ½ mile of major transitFull wording
1 space per ADU, in addition to the house's spaces; 'The only exception ... is when the accessory dwelling unit is located within one-quarter mile of a major transit stop.' (MMC 16.34.020(E), Ord. 1040) State law (RCW 36.70A.681(2)(a)(i)) bars ADU parking requirements within one-half mile of a major transit stop, so the half-mile rule governs.
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 — ADUs 'shall be fully contained within and attached to a single-family dwelling, or located within a detached accessory building' (MMC 16.34.020(B), Ord. 1040) in the single-family zones (R-16, R-20, R-30, SR-30). Not allowed on lots with critical areas or their buffers, on lots without public sewer (16.34.020(D)(3)), or within shoreline jurisdiction (16.34.020(D)(4))
Minimum lot size
ADUs only on lots meeting the minimum lot size for the principal unit (MMC 16.34.020(D)(2)): R-16 16,000 sq ft, R-20 20,000 sq ft, R-30/SR-30 30,000 sq ft net (MMC Table 16.22.020). No ADUs on undersized lots created by a subdivision or lot split
Do you have to live there?
No — MMC 16.34.020 (Ord. 1040) has no owner-occupancy requirement; the owner signs and records a registration agreement to keep the ADU compliant (16.34.020(H)–(I))
Can it be sold on its own?
Yes — 'The creation or sale of condominiums consistent with State law is allowed', limited to the lot's maximum dwelling units (MMC 16.21.060(E), Ord. 1040)
Pre-approved plans
None found
How long the city takes
Not published
Impact fees
Not found; RCW 36.70A.681 caps ADU impact fees at 50% of the principal unit's
Plans Medina has already approved.
A pre-approved plan skips the design review: Medina has already checked the drawings, so the permit review is about your lot.
Loading the plans…
Pictures are the official pages’ own. A pre-approved plan is not a permit: the city still reviews your site.
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 Medina 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 Medina municipal code and the city’s own pages on November 5, 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.
6 sources, read November 5, 2026
- mccmeetingspublic.blob.core.usgovcloudapi.net/medinawa-meet-e09a0b7dd9a8415e8501180474fbeb85/ITEM-Attachment-001-2b3abe397e0a430781e31d216f82e44d.pdf (Ord. 1040 final council draft: 16.21.060, 16.34.020)
- mccmeetingspublic.blob.core.usgovcloudapi.net/medinawa-meet-df66bebbcc6646e6b107a5adda77441c/ITEM-Attachment-001-224a767edfc744b19c00f8e1b569da7e.pdf (May 28, 2025 staff summary of adoption)
- www.medina-wa.gov/sites/default/files/fileattachments/development_services/page/18077/ordinance_no._1062_development_impacts_phase_1.pdf (Ord. 1062, setbacks)
- mccmeetingspublic.blob.core.usgovcloudapi.net/medinawa-meet-55f04049bac5494e9ce4c25df586e548/ITEM-Attachment-001-b6113bd98ba24d158fa66143176229eb.pdf (MMC 16.22–16.23 tables, unchanged by Ord. 1040)
- codified MMC at https://library.municode.com/wa/medina/codes/code_of_ordinances (not readable by automated tools)
- 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 Medina allows, what could fit, and a planning cost range. Free, no obligation.