Vancouver ADU Builder

An ADU is a home, and your lot decides which one you can build

Whether it's a backyard cottage, a garage conversion, or a basement unit, an ADU lives or dies on zoning, setbacks, and how the utilities connect. JDI Construction is a family-owned, Vancouver-based design-build remodeler, and we treat an accessory dwelling unit as exactly what it is — a second, independent home — so we start by confirming what your specific Vancouver property actually allows before anyone draws a floor plan. Vancouver is where we're based, and the housing here is a real mix: older lots near the Columbia River and downtown alongside newer subdivisions off I-5 and I-205, and no two parcels answer the ADU question quite the same way.

Our designers and trades work under one roof, so the unit you sign off on is already grounded in what the site and the code permit — we don't pass a hopeful sketch to an outside crew and discover at the counter that it won't pass. Here's the range of ADUs we build, what determines what's possible, and what to expect on cost and timeline.

The parts that matter most

Before a single wall is designed, a handful of factors decide the whole project:

A few decisions worth making early

The choices that make or break an ADU land well before design. The first is feasibility, and it matters more in Vancouver than people expect: ADU rules — size limits, setbacks, height, parking, and fees — are jurisdiction-specific, set here by Washington and by the City of Vancouver or Clark County, and they are not the rules that apply across the river in Portland. We confirm what your parcel permits before drawing anything. 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 the unit is a rental, a place for family, or a home office pushes the layout in different directions. 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. We work through all of it up front.

What Vancouver homeowners build ADUs for

The ADUs we're asked about across Vancouver tend to serve one of a few purposes: a rental for steady income, a private space for aging parents or adult children, or a quiet home office or studio set apart from the main house. Each one steers the design — a rental leans toward durable finishes and a separate entrance, a multigenerational unit toward single-level, step-free living, a workspace toward daylight and sound separation.

Because Vancouver sits in Clark County, the governing rules are Washington's and the city's or county's, which differ from Portland's just across the Columbia — one more reason we confirm what your parcel allows rather than assume. Whatever the use, we design the compact footprint to live larger than its square footage, with the light, storage, and ceiling height that keep a small home from ever feeling cramped.

What does an ADU cost in Vancouver?

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 come size and finish level, and then the part homeowners most often underestimate — the site and utility work. Running sewer, water, and power to a new dwelling, handling grading and access, and covering connection fees can claim a real share of the budget, which is precisely why we scope them early rather than late. 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 guess.

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 standard remodel because it pulls in zoning and utility review, so we build that time into the plan instead of promising a quick turnaround. Once permits are in hand, construction depends on the type — a conversion moves faster than a ground-up cottage. We give you a realistic schedule after the feasibility check, manage the permitting ourselves, and keep you posted through our client portal as the unit takes shape.

Why homeowners in Vancouver 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 the first stud 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. Vancouver is home for us, so we're minutes away and 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 Vancouver and the greater Clark County–Portland metro since 2007.