MNBE designs, permits, and builds ADUs, DADUs, and custom homes across Sammamish, one licensed team from first site visit to final inspection.
One licensed, bonded team for the whole job, from design and Sammamish Community Development permitting to fixed price construction.
Where a Klahanie or Pine Lake lot's land value justifies it, we replace an aging home with a ground up custom home, with feasibility run honestly first.
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Detached, attached, and basement ADUs, up to two per lot and 1,000 sq ft each under Sammamish's updated 2024 ADU code.
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Drawings built to clear Sammamish Community Development the first time, wooded plateau lots and critical areas included.
Explore ServiceWhy MNBE in Sammamish
We design ADU submittals to land clean at Sammamish Community Development, anticipating the corrections their reviewers send back before we file. Sammamish runs a smaller, residential focused queue, and on the plateau the geotechnical studies and critical area buffers are where permits actually slow down, so we manage them up front. Every submittal and every response is handled by us, never a third party expediter.
The Sammamish Plateau is laced with wetlands, streams, erosion hazard areas, and landslide slopes, and the city's critical area code carries a 50 foot buffer from the top and toe of a slope along with strict shoreline setbacks around Pine Lake, Beaver Lake, and East Lake Sammamish. A detached ADU has to sit fully outside those buffers, so we map the constraints first, coordinate the geotechnical report and its required third party peer review early, and design foundations and drainage to the grade instead of letting a buffer kill the project late.
Our detached ADU one town over in Redmond, full framing, roofing, kitchen, siding, and HVAC, finished and passed every inspection. We build the same way across Sammamish. See the full project, and the homeowner's verified five star review, on the project page.
What We Build in Sammamish
A freestanding backyard cottage with its own entrance and address, the strongest rental performer. Sammamish allows detached ADUs up to 1,000 square feet at 24 feet, and the large suburban lots in Klahanie, Trossachs, and Aldarra take one comfortably. The detached unit just has to sit outside every critical area buffer and shoreline setback, which is why we site it before we draw it.
Connected to the main house by a shared wall or addition, sized up to 50 percent of the primary home or 1,000 square feet, whichever is larger. Sammamish allows up to two ADUs per lot with no owner occupancy requirement, so both units can be rented, and an attached unit often clears critical area review more easily than a detached one on a wooded or sloped parcel.
The sloped, wooded sites across Pine Lake, Beaver Lake, and Inglewood Hill mean daylight and walkout basements are common in Sammamish's 1990s and 2000s homes, and the code expressly allows converting them into legal dwellings with a separate entrance, full kitchen, and code compliant egress. A basement conversion wholly within the lower level can even exceed the 1,000 square foot cap.
On many Sammamish lots, especially the larger parcels in Sahalee, Aldarra, and along East Lake Sammamish, land value justifies replacing an aging home outright. We run that feasibility honestly, sometimes the right answer is a ground up custom home, not a remodel, and build it under the same license and fixed price contract.
FAQ
Answering the questions Sammamish homeowners ask us most about building an ADU.
Yes. Under Sammamish's updated zoning code and Washington's HB 1337, most lots with a detached home allow up to two ADUs, as two detached, two attached, or one of each, with no owner occupancy requirement. The real constraint is critical areas, not unit count: a detached ADU must sit fully outside every wetland, stream, slope, and shoreline buffer, so siting comes first.
A typical ADU or residential permit in Sammamish runs about three to four months, and the Community Development Department's smaller residential queue is more predictable than Seattle SDCI. The big variable is critical areas: geotechnical third party peer review, landslide and erosion buffers, and wetland or stream studies can add weeks to months, so a steep, wooded, or wet lot can rival Seattle timelines.
Cost is site specific on Sammamish lots, so we don't quote a generic per square foot number. The real drivers are slope, the geotechnical report and its required peer review, critical area buffers, and how much clearing, grading, and drainage the site demands. After a free site visit we confirm the constraints and give you one fixed price for design, permitting, and construction.
Thank you for considering MNBE for your Sammamish ADU or custom home. We respond within one business day, Monday through Saturday.
We design and build across Sammamish, from the flatter upland lots in Klahanie and Trossachs to the steep, wooded, view streets around Pine Lake, Beaver Lake, Sahalee, and East Lake Sammamish. On the plateau the work is geotech heavy by default, so we plan the foundation, drainage, and critical area review for each parcel rather than treating every lot the same.