ADU Building in Sammamish, WA

If you are looking into ADU building in Sammamish, WA, DIGS Construction designs, permits and builds detached backyard cottages (DADUs) and attached ADUs for Plateau homeowners, from Pine Lake to Klahanie. Sammamish lots tend to be roomier than city lots in Seattle, which gives you more options for where a second home can sit, but the city's own permit rules, sensitive-area maps and, on some streets, septic systems decide what actually gets built.

We handle all of it under one roof: design, permits, site work and construction. When you call or message us, you talk with the owner, Eric Dexter.

What ADU building in Sammamish, WA involves

Most of Sammamish was built out as single-family subdivisions from the 1980s through the 2000s. Many of those homes sit on generous lots with long driveways and mature trees. That shapes an ADU project in a few ways:

• City permits, not county. Sammamish is in King County, but it is its own city, so building permits go through the City of Sammamish at City Hall on 228th Avenue SE, not King County's permitting office. We prepare and submit the drawings and respond to plan review comments for you.
• Sensitive areas. The Plateau has wetlands, streams and steep slopes, especially on the edges dropping toward Lake Sammamish. If any part of your lot is mapped as a critical area, setbacks and buffers can limit where an ADU goes. We check this before design starts.
• Sewer or septic. Much of the city is on sewer, but some lots still rely on septic. A septic system's capacity and drainfield location can decide whether an ADU works and where it sits on your lot.
• Stormwater. Our wet winters mean the city will look at how roof and driveway runoff from a new structure is handled, which affects site work.
• HOA covenants. Many Sammamish neighbourhoods have homeowner associations. It is worth reading your CC&Rs early; we can help you understand what they mean for a backyard cottage.

Washington's HB 1337 now requires cities like Sammamish to allow up to two ADUs on most residential lots. We confirm the current city code for your specific parcel before anything is drawn.

What an ADU costs in Sammamish, WA

Our all-in pricing for ADUs and DADUs starts at $375K. "All-in" means design, permits, site work and construction are in one number, not added on later. Where your Sammamish project lands above that depends on:

• Size and layout: a studio cottage versus a two-bedroom DADU.
• Detached or attached: a stand-alone backyard home, an addition, or a garage conversion.
• Utility runs: long driveways and deep lots mean longer water, power and sewer lines. Septic upgrades add cost.
• Site conditions: slope, tree protection, critical-area buffers and the foundation your soil needs.
• Stormwater work required by the city.
• Finish level: cabinets, flooring, windows and fixtures.

We would rather give you a realistic number at the first meeting than a low one that grows. One of our clients, Janis Ryerson, put it this way: "Eric presented a reasonable budget, and stuck to it."

How an ADU project in Sammamish, WA runs

1. Free consultation. We talk through your goals, whether that is a home for a parent, rental income or a home office, and your budget.
2. Site and feasibility check. We look at your lot, zoning, setbacks, critical areas, utilities and any HOA limits.
3. Design. We develop a plan that fits your lot and budget, starting from proven floor plans or drawing a custom one.
4. Permits. We submit to the City of Sammamish and manage plan review until the permit is issued.
5. Site work. Excavation, utilities, foundation and drainage, done by our own crew.
6. Construction. Framing through finishes, with Eric walking the site.
7. Final inspection and keys. We close out the permit and hand you a finished home.

Why Sammamish homeowners choose DIGS Construction

• Owner-led since 1989. Eric Dexter has more than 37 years in construction and is the person you speak with from the first call to final inspection.
• Proven builds. We have completed more than 100 DADUs and custom homes across greater Seattle.
• One team. With 13 in-house service lines, design, permitting and site work stay under one roof instead of being split across separate contractors.
• Rated 5.0 on Google. Our clients talk about budgets we keep and crews who show up.

Have questions before you call? Our ADU FAQ covers sizes, rules and what to expect.

Serving Sammamish, WA and nearby

We build across the Sammamish Plateau, including Pine Lake, Beaver Lake, Klahanie, Trossachs and the Sahalee area, and in neighbouring Issaquah, Redmond and Fall City. We work throughout King and Snohomish County, so if you are just off the Plateau, ask us.

Start your ADU in Sammamish, WA

If you are ready to find out what your Sammamish lot can hold, book a free consultation with DIGS Construction. Call Eric at (206) 900-6072 or send us a message and we will set up a time to talk through your property, your budget and your timeline.