Beaverton ADU Builder

A second home on your Beaverton lot — built to what the site allows

An ADU is a second, independent home on your lot — and on most projects the zoning and the utilities decide what's possible long before the design does. JDI Construction is a family-owned design-build remodeler, and that principle guides how we approach every accessory dwelling unit: it's a real second dwelling, not an oversized shed, so we confirm what your specific Beaverton property allows before we design to it. The Portland metro is known as unusually ADU-friendly, and that generally works in your favor here — but Beaverton sits in Washington County, the rules vary by jurisdiction, and every lot is different, so feasibility comes first. The mid-century ranch lots along the Sunset Corridor and the newer subdivisions around town each present their own possibilities, and the only way to know yours is to check.

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 the range of ADUs 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 decisions that make or break an ADU land well before design. First is feasibility. The metro's ADU-friendly reputation helps, but Beaverton's rules run through Washington County and the city, and they aren't identical to Portland's across the way — so we confirm what your specific lot permits before drawing a line. Second is type and use: a garage conversion, a basement unit, an attached addition, and a detached cottage differ sharply in cost and in what the site has to support, and whether you're building for rental income, family, or a home office shapes the plan. Third is budgeting for what's hidden — the sewer, water, and power connections and the system development charges that come with a new dwelling. We lay all of it out up front so there are no surprises once the design is done.

What Beaverton homeowners build ADUs for

The ADUs we're asked about in Beaverton usually serve one of a few needs: a rental unit that taps the region's ongoing demand for housing, a private space for aging parents or adult kids who want independence without leaving family, or a home office or studio kept separate from the main house. Each nudges the design a different way — a rental leans toward durability and its own entrance, a multigenerational unit toward single-level, accessible living.

Beaverton's housing stock helps here. The generous mid-century ranch lots around the Sunset Corridor often leave room for a detached cottage or a garage conversion, while newer subdivisions may point toward an attached or interior approach. 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 cramped.

What does an ADU cost in Beaverton?

ADU cost is driven first by type: a garage or basement conversion that reuses an existing structure generally runs less than a detached cottage built from scratch. After that come size, finish level, and — the part homeowners tend to underestimate — the site and utility work. Extending sewer, water, and power to a new dwelling, managing grading and access, and paying connection fees can be a real share of the budget, which is why we scope it early. With design and trades both in-house, we hand 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 average.

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 generally takes longer than a remodel because it involves zoning and utility review, so we fold that time into the plan rather than promising speed. Once permits are in hand, construction depends on the type — a conversion is quicker than a ground-up cottage. 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 Beaverton choose JDI

An ADU rewards a builder who knows the rules as well as the construction, because the project can stall at the permit counter long before framing begins. As a single accountable design-build team, we carry 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. Based just across the river in Vancouver, a short drive away, we stay close enough to be 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 Beaverton and the greater Portland–Vancouver metro since 2007.