Design-Build & Structural Engineering in Bothell, WA
ECD serves Bothell from our Bellevue office, about 13 miles and 25 minutes north on I-405. Bothell homeowners most often hire us for ground-floor additions, kitchen remodels that remove bearing walls in 1970s and 1980s houses, and ADUs on the larger lots of Westhill and Maywood.
Permitting a Bothell remodel across two counties
Bothell is one of the few cities in the region that sits in two counties: its southern part is in King County and its northern part in Snohomish County. Building permits are issued by the City of Bothell for the whole city, with applications through MyBuildingPermit.com, so the permit process is the same on both sides. What changes across the county line is everything around the permit: assessor records, utility districts for water and sewer, and in some cases older permit history held by the county before annexation.
For ADUs and additions with new plumbing, the utility district matters most. Different districts serve different parts of the city, each with its own connection requirements and fees. We identify your district at the start, because a sewer capacity letter or connection fee can affect both schedule and budget.
Bothell houses and what they mean for your remodel
Downtown Bothell has older houses on small lots near Main Street. Westhill, Maywood and the hillsides around them were built largely from the 1960s through the 1980s with ramblers, split-levels and early two-stories on larger lots. North Creek, Canyon Park and the Snohomish County side grew from the late 1980s onward with planned subdivisions and HOAs.
The most common Bothell remodel we see is a 1970s or 1980s house where the kitchen is closed off from the family room by a bearing wall supporting ceiling joists or the floor above. With crawlspace access below and an accessible attic, these walls are good candidates for flush beams with new footings, and the open kitchen that results transforms how the house works.
Site constraints common in Bothell
- Salmon-bearing streams including North Creek and the Sammamish River corridor, with buffers and floodplain rules.
- Wetlands in the North Creek valley that limit expansion on some lots.
- Steep slopes on the hillsides above the valley floors.
- Different utility districts by location, with their own ADU connection rules.
- HOA review in North Creek, Canyon Park and newer subdivisions.
Projects near Bothell
Project · Kirkland · Rose HillA full second story on a rambler, with new footings under the old wallsThree bedrooms and two baths added above a one-story house, designed to keep a low street profile.Bothell neighborhoods we serve
Canyon Park, Country Village area, Downtown Bothell, Maywood, North Creek, Queensborough, Thrashers Corner, Westhill.
Bothell questions
Remodeling in Bothell: common questions
Does it matter whether my Bothell house is in King or Snohomish County?
The city issues building permits for the whole of Bothell, so the permit process is the same. The county affects property records, which utility district serves you and where older permits may be filed. For ADUs and additions with plumbing, the utility district's rules and fees are often the bigger difference between the two sides.
Can I open my kitchen in a 1980s Bothell house?
Usually. In most houses of that era the kitchen wall carries ceiling joists or the upper floor and needs a beam, often a flush beam hidden in the ceiling. With crawlspace access, new footings under the posts are straightforward. Our engineer confirms the load and beam depth at the first visit.
Will North Creek wetlands limit an addition?
On lots near North Creek and its wetlands, buffers limit where new structures can go, and a wetland or stream report may be required. Many lots are outside the buffers entirely. We check critical area maps for your parcel during feasibility and place additions where buffers allow.
How do ADU utility connections work in Bothell?
It depends on your utility district. Some allow an ADU to share the main house's water and sewer service; others require separate connections or charge additional connection fees. We contact your district during feasibility for its ADU requirements so the budget reflects them before design.
Free estimate · Bellevue office
Talk to the engineer before you commit to a plan
A site visit, a scope conversation and a written budget range, at no cost.