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Standard plan profileD0

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.

Urban Acupuncture modeled standard plan

Repeatable program, parcel screening, schematic placement, and economics model — not City-pre-approved construction drawings.

Homes
2
Building type
One 480 square foot, one-story backyard cottage
Existing house
Keep as-is
Typical new footprint
16 × 30 ft
New-building height
1 story
New-home bedrooms
1 bedroom

Representative site plan

Existing house — retainedCottageSTREETREAR / ALLEYLot 52' (representative)N020 ftSchematic · not for permit

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

Simple-site low case through difficult-site high case.

Does it pencil?
Financing terms needed

Choose a loan share, rate, and amortization before showing financing break-even rent.

What to check first
Parcel-specific inputs

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, 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.

What must be true

  • A detached accessory dwelling unit is allowed on the lot
  • The rear yard can hold a 16 × 30 foot cottage and required clearances
  • Construction access and utility connections are practical

Verify before relying on it

  • Current Seattle DADU rules and site-specific permit requirements
  • Trees, drainage, utility route, access, and foundation conditions
  • Licensed construction drawings and contractor pricing

Check Low-cost backyard cottage at a Seattle address

Choose a parcel to open this exact model in the feasibility packet. We will test its screening match, place the program schematically, and adjust the economics with parcel data.

If the plan does not pass this parcel's screening, the packet will say so and offer other paths.

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 plans
Funding and programs that may apply

Programs that may pair with this plan

Matched from plan facts only. Parcel geography, income, utility territory, and owner facts can change the final list.

Browse all programs

Seattle Pre-Approved DADU Plans

Seattle SDCI / OPCD ADUniverse

Plan trigger

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

Plan trigger

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

May apply

Point-of-sale rebates for heat pumps, heat-pump water heaters, electrical panels, and related electrification work.

Up to $14,000 / household