Seattle houses hide things. We plan for that.
A large share of Seattle's single-family housing was built before 1950, and remodeling a house of that age is a different discipline from remodeling a 1995 tract home. Behind the plaster there may be knob-and-tube wiring, ungrounded circuits, galvanized supply lines that have narrowed to the diameter of a pencil, balloon framing with no fire blocking, and a basement that was finished at some point by someone who never pulled a permit.
None of that is a disaster. All of it is a budget item. The dishonest way to sell a Seattle remodel is to quote the visible work and discover the rest at the homeowner's expense. We open things up, look, and write the likely finds into the estimate as line items with numbers attached — so when we find them, you already know what happens next.
Neighborhoods we work in
Ballard · Fremont · Wallingford · Green Lake · Ravenna · Queen Anne · Magnolia · Capitol Hill · Madrona · Mount Baker · Beacon Hill · West Seattle · Phinney Ridge · Greenwood · Laurelhurst
Permits and inspections in Seattle
Seattle permits are issued by the Seattle Department of Construction and Inspections (SDCI), and the city's rules are their own — Seattle's residential code, energy requirements, tree protection and land-use rules differ in real ways from the Eastside cities we also serve. Structural work, additions, DADUs, most basement conversions and any change of use need permits, and older houses can also bring in electrical and plumbing upgrades that inspectors will expect to see brought current.
Seattle has also gone further than most Washington cities on backyard cottages and attached ADUs. Whether that helps your specific lot depends on the parcel, its zone and the current rules — we verify against your actual address before anyone pays for drawings.
What we build in Seattle
- Kitchen remodels in 1910–1940 bungalows and craftsmen, with the wiring and plumbing brought current
- Bathroom rebuilds in houses that never had a properly waterproofed shower
- Basement conversions into legal living space, with egress and ceiling height addressed
- Backyard cottages (DADUs) and attached ADUs where the lot and code allow
- Whole-house renovations including electrical service upgrades and insulation
- Rear additions and kitchen bump-outs on narrow city lots
Seattle at a glance
- Based in Kirkland — Seattle is a core service area
- We pull the permits and meet the inspectors
- Written, itemized estimates — no verbal numbers
- Bonded and insured in Washington
- Free walkthrough, written estimate
What Seattle lets you build in the back yard, in 2026
Washington rewrote the accessory dwelling unit rules statewide, and Seattle rewrote its code to match. Most of what homeowners here believe about ADUs is two or three years out of date.
| What people ask | Seattle, 2026 |
|---|---|
| How many you can build | Two on the same lot as the house — and both may be detached, in one structure |
| Biggest detached unit | 1,000 sq ft gross, not counting up to 250 sq ft of garage or an underground storey |
| Height | 32 ft plus the pitched-roof allowance — the same as a house. It was 14 to 18 ft until January 2026 |
| Parking | None. No off-street parking is required for an accessory dwelling unit anywhere in Seattle |
| Can you sell it separately | As a condominium, yes. Seattle does not allow an ADU to be subdivided off the main house |
| Owner occupancy | Not required. Washington abolished it statewide under RCW 36.70A.681 — you do not have to live on the lot to have an ADU, and you may rent both units |
| Who issues the permit | Seattle Department of Construction and Inspections (SDCI) |
Worth knowing in Seattle
Seattle's zoning changed on 21 January 2026: height to 32 ft, lot coverage to 50 percent, two DADUs per lot. Every one of the seven plans in the current pre-approved gallery was drawn for the old envelope — they are legal, and they leave part of your lot unused.
Ready-made plans
Seattle's ADUniverse gallery holds seven pre-approved plans plus more than 160 competition designs from 90 firms. The working set is licensed from the designer for up to $1,000; permit review drops from four to eight months down to two to six weeks. ADUniverse 2.0, drawn to the new code, lands in November 2026.
Source: SMC 23.42.022 and Chapter 23.44 as amended by the One Seattle Plan, effective January 2026, plus RCW 36.70A.681. Checked 4 September 2026. Codes in this region are being rewritten faster than any web page keeps up with — we verify your parcel against the code in force on the day we submit, not against a summary.
Four ways to add a unit — a new detached building, the garage, the basement or a suite inside the house — with a calculator that takes your own numbers: see all four and what each returns →
What it costs: a new detached unit on the Eastside runs roughly $325,000 to $550,000 all in, and advertised "starting at" prices leave out $120,000 to $180,000 of site, utility and permit work. Here is the whole number, line by line →
Building in Seattle: what works in your favor
- Seattle’s new ADU code took effect January 21, 2026 — we design to the current rules, not the outdated guides still circulating online.
- Permits go through SDCI (Seattle Department of Construction & Inspections) — a different system than Eastside cities, and we handle it routinely.
- School impact fees are currently waived for ADUs in Seattle.
Statewide, Washington law (HB 1337) is on your side in Seattle: up to two ADUs are allowed on most residential lots, a detached ADU may be up to 24 ft tall with side and rear setbacks of no more than 5 ft, units up to 1,000 sq ft must be permitted, there is no owner-occupancy requirement, and no parking can be required near major transit.
Rules change and every lot is different — we verify your exact address with the city before any design work. This page is information, not legal advice.
Seattle questions we get asked
Our house has knob-and-tube wiring. Does it all have to go?
Do you build backyard cottages in Seattle?
Are you a Seattle company or an Eastside company?
Nearby areas we serve
Building in Seattle? Let's talk.
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Tell us about your project — we'll come out, listen, and give you an honest number.
Call or text(425) 866-3940Email: office@nwhomesremodel.com
Hours: Mon–Fri 8:00 AM – 6:00 PM · Sat by appointment
Based in Kirkland, WA — serving the Eastside and Greater Seattle