( Services — Everett, Seattle & the Eastside )
Additions& ADUs.
More house, on the land you already own. Bump-outs, second stories, garage conversions and backyard cottages — built to look like they were always there.
( 01 )
Washington changed the rules in your favor
Recent state legislation pushed cities across Snohomish and King County to permit ADUs broadly — commonly two per lot, with old owner-occupancy requirements and most parking-replacement mandates removed. Projects that were impossible five years ago are now routine.
What has not changed is that every parcel is different. Size, height and setback limits are still local, which is why the honest first step is a feasibility read on your specific lot rather than a rule of thumb.
( 02 )
Four ways to add space
A ground-level addition is the most straightforward: new foundation, framing, and a roofline tied in so it does not read as bolted on. A second story doubles bedroom count without losing yard, at the cost of structural work below. A garage conversion is the cheapest square footage above grade because the shell already exists. A detached ADU is a small house in the back — the most expensive option and the only one that pays rent.
Which one fits depends on your lot, your budget and whether the space needs to be independent. We price the realistic options side by side rather than quoting the biggest one.
( 03 )
Matching the existing house
An addition succeeds when nobody can tell where the old house ends. Rooflines tied in cleanly, siding and window profiles matched, floor heights aligned. That is finish craft, and it is the difference between adding value and adding square footage.
Typical investment
Broad Seattle-area ranges, not quotes — your written estimate is free and itemized.
| Tier | Range | What it covers |
|---|---|---|
| Garage conversion | $40k–$150k | Living space at the low end; full ADU with kitchen, bath and entrance at the high end. |
| Ground-level addition | $250–$450/sq ft | Foundation, framing, envelope, systems and finishes, tied into the existing house. |
| Second story / detached ADU | $350–$550/sq ft | Structural work below, or a standalone unit with its own foundation and utilities. |
Home Additions & ADUs questions
- How much does a home addition cost?
- Ground-level additions typically run $250–$450 per square foot all-in around Seattle; second stories run higher because the existing structure must carry the new load. A 400 sq ft addition is realistically a $100k–$180k project.
- Can I build an ADU on my lot?
- Most likely. Washington now allows ADUs broadly across Snohomish and King County, often two per lot, without owner-occupancy requirements. Local size and setback rules still vary, so we confirm what your specific parcel allows at the free estimate.
- Is a garage conversion cheaper than an addition?
- Substantially — the slab, walls and roof already exist, so cost per usable square foot is often half that of ground-up construction. The trade-off is losing covered parking and storage.
- Do you handle addition permits and engineering?
- Yes. Additions need stamped drawings, usually structural engineering, and a building permit. We prepare and file the package and manage inspections through final sign-off as part of the project.
Free In-Home Estimate
Let’s talk about your place.
Free estimates across Everett, Seattle & the Eastside. You’ll talk directly to Eduard — no call centers, no sales layer.