Standard planD0
Low-cost backyard cottage
1 new home, existing house kept
A compact one-story cottage in the back yard — a rental, a home for family, or future flexibility. Modeled on simple, repeatable DADU plans and current backyard-cottage cost benchmarks.
Representative site plan
New: one 16×30 ft cottage. Drawn on a typical lot — every real lot differs, so this is illustrative, not a site-specific layout.
The program
2 homes — 1 market cottage (16x30 ft) in the rear yard.
+1 net new home per lot (market-rate).
Workbook-baseline economics
This cottage is modeled to cost $275K–$425K; loan terms are needed before comparing rent with a financing break-even payment.
- Modeled all-in cost
- $275K–$425K
- Does it pencil?
- Financing terms needed
- What to check first
- Parcel-specific inputs
Simple-site low case through difficult-site high case.
Choose a loan share, rate, and amortization before showing financing break-even rent.
Representative workbook baseline — not adjusted for a specific parcel.
Illustrative workbook baseline — a real packet adjusts these with the parcel's own assessor, market, and rent data.
Where it fits
Lots where a backyard cottage (DADU) is allowed and the rear yard is clear enough for a small one-story home — roughly 92,000 lots citywide, with no transit requirement. The existing house stays; the cottage is a market-rate rental, so the public benefit is gentle, broadly available added density rather than an income-restricted home.
Closest Seattle pre-approved plan references
D0 is Urban Acupuncture's 16 x 30 ft site-and-financial model, not an architect's construction set. These City-listed plans explore a similar compact-cottage idea. Their exact parcel fit, current Standard Plan status, licensing, and site-specific permit work still need confirmation.
Browse all Seattle pre-approved plansPrograms that may pair with this plan
Matched from plan facts only. Parcel geography, income, utility territory, and owner facts can change the final list.
Seattle Pre-Approved DADU Plans
Seattle SDCI / OPCD ADUniverse
Pre-reviewed design plans intended to reduce design cost and speed review for eligible detached ADU projects.
$1,000 / project
Home Improvement Property Tax Exemption
King County Assessor / RCW 84.36.400
Temporary property-tax exemption on qualifying added improvement value.
Exempts added value up to 30% of original structure value
Washington HEAR Home Electrification Rebates
Washington Department of Commerce / local HEAR administrators
Point-of-sale rebates for heat pumps, heat-pump water heaters, electrical panels, and related electrification work.
Up to $14,000 / household