West Linn ADU Builder

An ADU in West Linn begins with the lot, not the layout

Portland is one of the most ADU-friendly cities in the country, yet every lot is different, so a feasibility check comes before a floor plan. JDI Construction is a family-owned, Vancouver-based design-build remodeler, and we treat an accessory dwelling unit as a real second home that has to earn its place on your specific parcel — which is why we confirm what your West Linn property actually allows before we design to it. In a town of wooded, larger lots stepping down toward the Willamette and the Tualatin, that groundwork matters: the same rule can play out very differently on a sloped, tree-lined site than on a flat one.

Our designers and trades work as one team, so the unit you approve is grounded in what the site and the code actually permit — we don't hand a hopeful floor plan to a separate crew and find out later it won't pass. Here's what we build, what decides what's possible, and what to expect on cost and timeline.

Types of ADUs we build

"ADU" covers several very different builds, and the right one depends on your lot, your budget, and how you'll use it:

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   Detached (DADU)A standalone backyard cottage — the most flexible, and the most site-dependent.
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   Attached ADUAn addition with its own entrance, kitchen, and bath, tied to the main house.
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   Garage conversionTurning an existing garage into a living unit, often the most cost-effective route.
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   Basement / interiorConverting lower-level or interior space into a self-contained unit.

A few decisions worth making early

The choices that make or break an ADU come well before design. The first is feasibility: Oregon has opened the door to ADUs statewide, but the details — size caps, setbacks, height, parking, and fees — are set locally, and what West Linn permits is not identical to Lake Oswego or the City of Portland next door. We confirm what your specific lot allows before drawing anything, and on West Linn's larger wooded parcels that also means reading the slope, the tree cover, and how a unit can be reached. The second decision is type and use: a detached cottage, a garage conversion, a basement unit, and an attached addition carry very different costs and site demands, and whether you're building for rental income, family, or a quiet workspace shapes the plan. The third is budgeting for the parts you can't see — the sewer, water, and power connections and the system development charges that come with adding a dwelling.

What West Linn homeowners build ADUs for

Most West Linn ADUs we're asked about serve one of a few purposes: a rental for income, a private and independent space for aging parents or adult children, or a studio or home office set apart from the main house. Each pulls the design in a slightly different direction — a rental leans toward durability and a separate entrance, while a multigenerational unit favors single-level, step-free living.

Because so many West Linn lots are generous and set among trees, a detached cottage is often on the table here in a way it isn't on a tight in-town lot — but that same setting brings grade and access to think through. Whatever the use, we design a compact footprint to live larger than its square footage, using light, storage, and ceiling height to keep a small home from feeling small.

What does an ADU cost in West Linn?

ADU cost is driven first by type: a garage or basement conversion that reuses an existing structure generally costs less than a detached cottage built from the ground up. After that it's size, finish level, and — the part homeowners often underestimate — the site and utility work. On West Linn's sloped, wooded lots, grading, access, and running sewer, water, and power to a new dwelling can be a real share of the budget, along with the connection and system development charges. That's exactly why we scope those items early. With design and trades both in-house, we give you an itemized estimate once we know what your lot allows and which type fits, so the number reflects your project rather than a generic per-square-foot figure.

How long does an ADU take to build?

An ADU runs on three clocks: feasibility and design, permitting, and construction. Permitting for a second dwelling can take longer than a straightforward remodel because it involves zoning and utility review, so we build that time into the plan rather than promising a quick turnaround. Once permits are in hand, construction depends on the type — a conversion moves faster than a ground-up cottage, and a sloped site can add site-prep time. We give you a realistic schedule after the feasibility check, handle the permitting, and keep you updated through our client portal as the unit comes together.

Why homeowners in West Linn choose JDI

An ADU rewards a builder who understands the rules as well as the construction, because the project can stall at the permit counter long before the first wall goes up. As a single accountable design-build team, we handle the feasibility, the design, the utility connections, and the build under one roof, so nothing gets lost between a zoning question and the crew on site. We manage the permitting, keep you informed through our client portal, and stand behind the work with a five-year workmanship warranty. West Linn is a short drive from our Vancouver home base, close enough for us to stay responsive throughout a project this involved.

JDI Construction — "Built by family. Trusted by neighbors." Design-build remodeling and ADU construction based in downtown Vancouver, WA, serving West Linn and the greater Portland–Vancouver metro since 2007.