Tigard ADU Builder

An ADU is a full building — and in Tigard the site work sets the terms

An ADU is a real building with its own kitchen, bath, and utilities, which is why the site work and connections drive as much of the cost as the walls do. JDI Construction is a family-owned design-build remodeler, and we treat an accessory dwelling unit as exactly that — a second, independent home on your lot, where the zoning and the utilities decide what's possible before the design does. The Portland metro is generally very ADU-friendly, which usually works in a Tigard homeowner's favor, but rules still vary by city and jurisdiction and every lot differs, so we confirm what your specific property allows before drawing anything. Tigard is established suburban Southwest metro, threaded by Highway 99W, and its settled lots each come with their own setbacks, grades, and utility runs that shape what a second unit can be.

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.

What decides what you can build

Before a design carries any weight, a few factors set the outer edges of what your lot can support. These are the ones we confirm first:

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   Zoning & size limitsWhat your lot's zone allows for a second unit — in size, height, and placement.
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   Setbacks & coverageHow close to property lines and how much of the lot a unit can occupy.
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   Parking & accessWhether parking is required and how the unit is reached from the street.
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   Utilities & feesSewer, water, and power connections, plus the system development charges that come with them.

A few decisions worth making early

The decisions that make or break an ADU come well before design. First is feasibility. Tigard benefits from the metro's ADU-friendly climate, but its rules are the city's and the county's, not automatically Portland's, and no two lots behave the same once slope, access, and existing utility lines factor in — so we confirm what your parcel permits before drawing. Second is type and use: a garage conversion, a basement unit, an attached addition, and a detached cottage differ widely in cost and in what the site must support, and building for rental income, family, or a home office shapes the layout. Third is budgeting for what you can't see — the sewer, water, and power connections and the system development charges that a new dwelling brings. Because an ADU is a full building, those connections often carry more of the budget than homeowners expect, so we scope them up front.

What Tigard homeowners build ADUs for

The ADUs we're asked about in Tigard tend to serve one of a few purposes: a rental unit that leans on the region's ongoing housing demand, a private space for aging parents or adult children who want independence close to home, or a home office or studio kept apart from the main house. Each points the design somewhere different — a rental favors durability and its own entrance, a multigenerational unit favors single-level, accessible living.

Tigard's established suburban lots often leave room for a detached cottage or a garage conversion, and near the 99W corridor the mix of older and updated homes opens up interior and attached routes as well. 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 Tigard?

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, finish level, and — since an ADU is a full building — the site and utility work, which homeowners routinely underestimate. Extending sewer, water, and power to a new dwelling, handling grading and access, and paying connection fees can be a substantial share of the budget, which is why we scope it 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 generally takes longer than a remodel because it involves zoning and utility review, so we build that time into the plan rather than promising a fast 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, handle the permitting, and keep you updated through our client portal as the unit comes together.

Why homeowners in Tigard 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 framing starts. 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 back 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 through a project this involved.

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