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Phase 0 · Feasibility · Step 0.1

Confirm zoning, height, setbacks, and building coverage for your lot

Pull your parcel up on Portland Maps and read the dimensional rules in Title 33 for your zone — height, setbacks, and building coverage tell you whether a second story actually fits before you spend a dollar.

Who
Homeowner
How long
1-2 days
Cost
Free
You end up with
Portland Maps zoning report + height/setback/coverage numbers for your lot

If you skip this: A handful of Portland lots are at their building-coverage cap already because of an existing rear addition or a wide footprint. Check this first and you'll know in an afternoon whether the addition is a real option or whether you're looking at a ground-floor remodel instead.

Start here

Portland's zoning code controls three numbers that decide whether a second story fits on your lot: height limit, setbacks, and building coverage. All three are public, all three are tied to your specific zone, and all three are looked up in the same place.

How to do it

  1. Open Portland Maps and enter your address.
  2. Note the base zone — most older Portland houses are in R5 (5,000 sf minimum lot area) or R7. Some inner-east neighborhoods are R2.5; outer east is often R10.
  3. Open Title 33.110 and look up the dimensional rules for your zone.
  4. Make a one-page note: existing height, height cap, existing setbacks vs. required, current building coverage vs. cap.

What you're looking for

  • Height limit. R5 and R7 are typically capped at 30 ft to the highest point, with a few feet of additional allowance for a pitched roof. A one-story bungalow at ~16 ft has comfortable headroom for a second story; a 1.5-story with a steep roof might not.
  • Setbacks. Front, side, and rear minimums apply to the second story too. If the existing house is non-conforming on a side setback (a common situation on narrow inner-east lots), a second story stacking directly above it may need an adjustment.
  • Building coverage. Footprint plus most projecting elements as a percentage of lot area. A second story doesn't change footprint, so this number stays the same — but if you're also pushing out the ground floor, it matters.
  • Maximum floor area. Title 33.110 caps the total above-grade floor area on most R-zone lots; the formula varies by zone and lot size. A 1,200 sf house on a 5,000 sf R5 lot is well under the cap; a 2,000 sf house on the same lot is close to it.

What this tells you

  • All four numbers have headroom? A second story is feasible from a zoning standpoint. Move on to the permit-history check.
  • You're already at the floor-area or coverage cap? A second-story addition isn't realistic without a Type II adjustment. The realistic alternatives are a ground-floor remodel or a DADU instead — at which point the Portland DADU workflow is the better project.

A quick note on RIP and middle housing

Portland's Residential Infill Project (RIP) reforms took effect 2021-08-01 and broadened what's allowed in single-dwelling zones — duplexes, triplexes, sometimes fourplexes on most R-zone lots. RIP changed the unit-count story; it didn't relax the dimensional rules. Height, setbacks, and floor-area caps still control whether a second story fits.

Where this information came from

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