Oregon City ADU Builder

What your Oregon City lot allows comes first

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, Vancouver-based design-build remodeler, and we believe an accessory dwelling unit should be designed to the property it's going on, not to a stock plan — so we start by confirming what your specific Oregon City parcel actually permits. In one of Oregon's oldest towns, that mix matters: an older bluff home near the historic core and a newer house up in a hilltop subdivision can face very different site and utility realities on the same question.

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 is broadly ADU-friendly, but the specifics — size limits, setbacks, height, parking, and fees — are decided city by city, and what Oregon City allows differs from unincorporated Clackamas County or the City of Portland. We confirm what your specific lot permits before drawing anything, which matters especially on an older bluff property where an aging main house, existing utilities, and tighter historic-area lots all shape what fits. The second decision is type and use: a garage conversion, a basement unit, an attached addition, and a detached cottage carry very different costs and site demands, and whether you're building for rental income, family, or a home office points the layout in a different direction. 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 Oregon City homeowners build ADUs for

Most Oregon City ADUs we're asked about come down to a few uses: a rental for income, a private space for aging parents or adult children, or a studio or office set apart from the main home. Each one steers the design differently — a rental favors durability and its own entrance, a multigenerational unit favors single-level, accessible living.

The town's split character shows up here too. On the older bluff lots, a basement or interior conversion or a garage unit can make good use of what's already built, while the newer hilltop subdivisions often have the yard room for a detached cottage. Whatever the use, we design a compact footprint to live larger than its square footage, with the light, storage, and ceiling height that keep a small home from feeling small.

What does an ADU cost in Oregon City?

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 an older bluff property, connecting sewer, water, and power to a new dwelling and tying into aging systems can add up; on a newer hilltop lot, grading and access may be the bigger line. Either way there are connection and system development charges to account for, which is why we scope them 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 remodel because it involves zoning and utility review — and in Oregon City's historic areas, that review can carry additional steps — so we build that time into the plan rather than promising a quick turnaround. Once permits are in hand, construction depends on the type, with a conversion generally faster 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 Oregon City 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. Oregon City 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 Oregon City and the greater Portland–Vancouver metro since 2007.