ADUs & conversions · Sammamish, WA
Basement ADU Conversion in Sammamish, WA
Turn a basement into a separate-entry dwelling unit.
Basement ADU Conversion in Sammamish, WA
When Sammamish homeowners search for basement ADU conversion or a dependable adus & conversions contractor near them, they want craftsmanship that lasts and a crew that communicates. That's exactly what we do. Turn a basement into a separate-entry dwelling unit.
Sammamish plateau homes are often large and family-focused, where additions, kitchens, and outdoor living spaces deliver the most lasting value.
We write scope in plain terms: what we'll do, the materials, the sequence, and how any surprises are handled if something is uncovered.
What's included in your basement ADU conversion
A typical basement ADU conversion in Sammamish can involve permits, framing, the kitchen and bath, foundation — and we put the full scope in writing so you know exactly what's covered before work starts.
You get a single point of contact, licensed and insured trades, and clear communication from the first sketch to the final walkthrough.
How much does a basement ADU conversion cost in Sammamish?
Most basement ADU conversion projects in Sammamish 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 Sammamish homeowners choose Xion Build
One dedicated point of contact coordinates the entire job, so you're never chasing subcontractors or wondering who's responsible.
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.
Our Sammamish adus & conversions process
Handoff includes a detailed walkthrough and a written warranty — not a crew that vanishes the moment the dust settles.
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.
Frequently asked questions
Are you a licensed adus & conversions contractor?
Yes — Xion Build is licensed, bonded, and insured in WA. Every project is built to meet or exceed code and is backed by a written warranty.
How much does a basement ADU conversion cost in Sammamish?
Most basement ADU conversion projects in Sammamish 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 Sammamish price reflects the actual project — not a guess.
Do you handle permits and inspections?
Yes. We manage permit applications, schedule inspections, and coordinate any required engineering so the work passes cleanly in Sammamish.
Do you offer a basement ADU conversion in Sammamish, WA?
Yes. Turn a basement into a separate-entry dwelling unit. Xion Build is a licensed, bonded, and insured adus & conversions contractor serving Sammamish and the surrounding WA communities.
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.
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