ADUs that earn back the build.
Rental income, aging-parent housing, adult-child housing, a serious home office. Portland and most surrounding jurisdictions have written ADU-friendly zoning, and we've been building under those rules since the regulations opened up.
The most useful structure you can add to a Portland lot.
ADUs add resale value, generate income, house family, and let you stay on a lot you love when the main house would otherwise be too small. More Portland-area lots are eligible than most homeowners realize, and the SDC and parking rules have moved in homeowners' favor.
For an attached suite that's part of the primary residence, see our mother-in-law suite page. For a basement carved into a separate-entrance unit, our basement finishing page covers the conversion.
Types of ADUs we build
- Detached new construction (DADUs). Standalone 400 to 900 sq ft units in the backyard. Most flexible design, highest cost, best resale
- Garage conversions. Existing garage to full ADU with kitchen, bath, separate entry. Most cost-effective when the structure is sound
- Garage with ADU above. New garage at ground floor with finished ADU above. Good option when you also need garage space
- Attached ADUs. Built off the side or back of the main house with separate exterior entrance
- Internal ADUs. Carved out of an existing basement or upper floor with a private entry
Real credentials. Verifiable.
Every license and rating below is independently verifiable.
Portland-area ADU regulations, the headlines
- Size limits. Most cities cap detached ADUs at around 800 to 1,000 sq ft. Portland is more permissive than many surrounding cities
- Setbacks. Detached ADUs typically need 5' to 10' rear and side setbacks; check your jurisdiction
- Height. Generally limited to 20' to 25', depending on jurisdiction
- Parking. Portland eliminated ADU parking requirements years ago. Some surrounding cities still require it
- Owner-occupancy. Portland and most surrounding cities have eliminated requirements. Some still require it
- Short-term rental. Rules vary widely; some allow STR of an ADU, some require long-term tenancy
- SDC waivers. Some jurisdictions have temporary or permanent SDC waivers that can save $20K to $40K+
We confirm what's allowable on your specific lot before we start designing.
How a Keyser ADU build runs
Feasibility, design, permit, build. 7 to 12 months total on a typical DADU.
Feasibility & site review
We walk the property, confirm what's allowable on your lot (size, height, setbacks, parking, SDC implications), and talk through what you want the ADU for. Free, no obligation.
Design, engineering, estimate
Plans tailored to use case and lot. Detached ADUs usually take 6 to 12 weeks of design. Engineering and energy modeling as required. Line-item estimate including SDCs, permits, utilities, contingency.
Permit, build, inspect
ADU permits in Portland-area jurisdictions typically take 6 to 14 weeks. Detached ADUs usually run 5 to 9 months of active build. Site work, foundation, framing, mechanicals, finishes. Final inspections and walkthrough.
Ready to put your lot to work?
Tell us about your property and how you want to use the ADU. We come out, walk it with you, and follow up with feasibility direction.
The honest math on Portland ADUs
- Rental income. A typical Portland-area ADU rents for $1,500 to $2,800 per month for long-term tenancy. That's $18K to $33.6K annual gross on a $300K to $450K build
- Resale value. Properties with permitted ADUs typically sell at a premium reflecting the income potential, though appraisal varies by neighborhood
- Family use. Hard to put a number on, but housing an aging parent on your property has value beyond income calculations
- Home office or flex space. If working from home is permanent, a dedicated separate-structure office can be life-changing
ADUs don't pay back like a stock investment. They make sense for owners who value income, flexibility, or housing family, more than they value the cash-on-cash return.
Typical Portland-area ADU pricing
Mid-2020s market. SDC fees are a real budget line that vary by jurisdiction; some cities offer waivers.
ADU FAQs
How long does an ADU take?
Can I rent out an ADU short-term?
Will an ADU affect my property taxes?
Can we finance an ADU?
Do I have to live in the main house?
How do we get started?
Recent Keyser Interior Work
Every project backed by our written warranty.
Workmanship warranty included in every contract, in writing. If something we built isn't right, we come back and make it right.
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Let's see what your lot can do.
Free site walk and feasibility consultation. Honest answer on whether an ADU pencils for your property.