Portland, OR
Backyard ADU plans in Portland, OR
A detached backyard ADU adds a self-contained studio or one-bedroom on your lot. Keeping the footprint at or under 800 sq ft matters more than any other design decision — it unlocks the most protective approval rules in several states and keeps costs in the range where rental payback math works.
ADU and small-dwelling rules vary by city — check local zoning, setbacks, and permit requirements before building. Several states now require streamlined ADU review; your local planning department is the authority.
What a 400 sq ft unit rents for around Portland
$1,320–$2,050/mo long-term · $110–$200/night short-term
Rough metro bands — an estimate, not advice. Run your own numbers.
Plans that fit this project
Studio ADU 20×20
400 sq ft · 0 bed · 1 bath
Narrow ADU 31×13
403 sq ft · 0 bed · 1 bath
Studio ADU 22×22 accessible
484 sq ft · 0 bed · 1 bath
Desert ADU 20×24
480 sq ft · 0 bed · 1 bath
1-bed ADU 30×21
630 sq ft · 1 bed · 1 bath
1-bed ADU 30×21 gable
630 sq ft · 1 bed · 1 bath
Container 8×20
160 sq ft · 0 bed · 0 bath
Container 8×40 high-cube
320 sq ft · 1 bed · 1 bath
Double container 16×40
640 sq ft · 1 bed · 1 bath
Park model 399
399 sq ft · 1 bed · 1 bath
Plans are design starting points checked against 2021 IRC geometry rules — not permit documents. Local codes and objective standards in Portland govern; confirm with your building department or a licensed professional.