ADU Feasibility in Portland: What to Evaluate Before You Design

Before investing in design or construction, understanding ADU feasibility in Portland is critical.

Lot size, zoning rules, setbacks, and height limits all affect whether an accessory dwelling unit can be approved.

Starting with a feasibility review helps prevent redesigns, delays, and permitting issues later.

Why ADU Feasibility Matters in Portland

Portland allows ADUs in many residential zones, but every property is different.

A feasibility review confirms whether a detached ADU, garage ADU, or two-story ADU is allowed based on

zoning, setbacks, and existing site conditions.

Evaluating feasibility early ensures your project aligns with development standards

before time is spent on full construction drawings.

How the ADU Feasibility Wizard Helps

Our interactive

ADU Feasibility Wizard

evaluates your lot across Portland and the surrounding PDX region, including Beaverton, Gresham, Hillsboro,

Salem, Keizer, and Marion County.

For a $250 upgrade, the Wizard allows you to download preliminary ADU plans for revision

or upload your own plans to confirm zoning compliance, setbacks, and development potential.

Two-Story and Garage ADU Considerations

Two-story ADUs over garages are common in Portland, but they require careful review of

height limits, floor area ratios, and setback reductions.

A feasibility check confirms whether this configuration is permitted before drafting begins.

Start With Feasibility Before Drafting

If you’re considering an ADU in Portland, start with feasibility first.

Use the

ADU Feasibility Wizard

to evaluate your lot, understand zoning constraints, and move forward with confidence.