Additions & accessory dwelling units

More room, without leaving the lot you already like.

Additions

Add the space where it actually helps.

A growing family, a parent moving in, someone now working from home full time — the house that fit five years ago stops fitting. An addition is usually cheaper than buying the same amount of space somewhere else in Whatcom County.

The engineering matters here more than anywhere. New square footage needs its own foundation, its own load path, and a roof that ties into the existing one without creating a leak. We handle the structural side, coordinate the engineering where it is required, and make the new work look like it was always there rather than bolted on.

Ground-floor room additions and bump-outs
Second-storey additions and roof raises
Primary suite additions
Garage conversions and garage additions
Sunrooms, covered decks and outdoor living space

ADUs

A second home on the same parcel.

Accessory dwelling units have become one of the most requested projects in Whatcom County — for ageing parents, for adult children who cannot afford Bellingham prices, and for rental income.

An ADU is a small house, and it has all the complexity of one: foundation, framing, full plumbing and electrical, a kitchen, heating, insulation, and its own connection to water and sewer or septic. Building one properly is not the same as finishing a garage.

We start by checking what your parcel actually allows, because that determines everything else. Zoning, lot coverage, setbacks, height limits, parking, and septic capacity all decide what is possible before a single line gets drawn.

Detached ADUs and backyard cottages
Attached and basement ADUs
Garage-to-ADU conversions
Parcel, zoning and utility feasibility checks before you commit
Full permitting with your city or with Whatcom County

Questions

Common questions

Can I build an ADU on my property in Whatcom County?

Very often yes, but the rules depend on whether you are inside a city limit or in unincorporated county, and on your lot size, zoning, septic or sewer capacity and setbacks. Washington State law has pushed jurisdictions to make accessory dwelling units easier in recent years. We check your specific parcel before you spend money on design.

Is an addition cheaper than moving?

Usually, once you account for agent fees, closing costs, moving costs and the price difference of a larger home in the same area. It also keeps you in your school district and on your lot. The exception is when your existing foundation or structure cannot carry what you want to add.

How disruptive is a second-storey addition?

It is the most disruptive thing we do. The roof comes off, so the work is weather-dependent and the house is unusable for part of it. Most families move out for that phase. A ground-floor addition or a garage conversion is far easier to live through.

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