ADUs & conversions · Seattle, WA
Basement ADU Conversion in Seattle, WA
Turn a basement into a separate-entry dwelling unit.
Basement ADU Conversion in Seattle, WA
Xion Build provides expert basement ADU conversion in Seattle. As a trusted Seattle adus & conversions contractor, we manage design, materials, permits, and every trade in-house so your project stays on schedule and on budget. Turn a basement into a separate-entry dwelling unit.
From Laurelhurst to Queen Anne, Seattle's older homes often need structural care alongside the kitchen, bath, and addition work that modernizes them.
You get a single point of contact, licensed and insured trades, and clear communication from the first sketch to the final walkthrough.
What's included in your basement ADU conversion
A typical basement ADU conversion in Seattle can involve foundation, utilities, the kitchen and bath, framing — and we put the full scope in writing so you know exactly what's covered before work starts.
We write scope in plain terms: what we'll do, the materials, the sequence, and how any surprises are handled if something is uncovered.
How much does a basement ADU conversion cost in Seattle?
Most basement ADU conversion projects in Seattle fall between $100,500 – $225,500, depending on the size of the space, the finishes you choose, and the condition of what's already there.
Because every home is different, we don't quote final numbers sight unseen. After a free in-home consultation you get a detailed, itemized estimate tied to your actual adus & conversions project — so there are no surprises later.
Why Seattle homeowners choose Xion Build
Meticulous job sites and clear daily communication, with respect for your home, your time, and your neighbors.
Licensed, bonded, and insured in Washington — every project is built to meet or exceed code and backed by a written warranty.
Local crews who know Eastside permitting, inspections, and the way Pacific Northwest weather tests a home.
Our Seattle adus & conversions process
We pull the permits, schedule every trade in the right order, and protect your home, landscaping, and daily routine throughout the build.
Each phase is inspected and documented, and we keep you updated so you always know what's happening and what's next.
Handoff includes a detailed walkthrough and a written warranty — not a crew that vanishes the moment the dust settles.
Frequently asked questions
How much does a basement ADU conversion cost in Seattle?
Most basement ADU conversion projects in Seattle run $100,500 – $225,500, depending on scope, finishes, and existing conditions. After a free in-home consultation we provide a detailed written estimate so your Seattle price reflects the actual project — not a guess.
How long does a basement ADU conversion take?
Timelines depend on scope and permitting. Once the plan is confirmed we give you a realistic schedule and keep you updated as the adus & conversions work progresses.
Do you handle permits and inspections?
Yes. We manage permit applications, schedule inspections, and coordinate any required engineering so the work passes cleanly in Seattle.
Do you offer a basement ADU conversion in Seattle, WA?
Yes. Turn a basement into a separate-entry dwelling unit. Xion Build is a licensed, bonded, and insured adus & conversions contractor serving Seattle and the surrounding WA communities.
Do you offer free estimates for basement ADU conversion near Seattle?
Absolutely. We provide free, no-obligation in-home estimates throughout Seattle and the greater Eastside, with transparent, itemized pricing.
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