Housing model profileA6b
Backyard quad behind house
5 homes, existing house kept
The existing house stays as-is, with four compact townhomes placed in the rear yard.
Urban Acupuncture housing model
Repeatable program, parcel screening, schematic placement, and economics model — not City-pre-approved construction drawings.
- Homes
- 5
- Building type
- Four three-story townhomes behind a retained house
- Existing house
- Keep as-is
- Typical new footprint
- 39 × 39 ft
- New-building height
- 3 stories
- New-home bedrooms
- 3 bedrooms
- You end up with
- 5 homes, existing house kept. Keep the existing home; add a compact 39 × 39 foot rear-yard quad.
- You put in
- Land or development rights, plus project funding if you build yourself. An outright sale and a land-contribution partnership are different deals.
- Your role
- Keep the existing home while developing the additional homes; confirm construction disruption and access. Choose between seller, development partner, or owner commissioning the build.
- Timeline
- Feasibility and deal terms → design, permits and tenure review → construction → individual sales. A project-specific schedule is required.
- It works when
- A transit-served neighborhood-residential lot with a clear rear yard; At least about 49 feet of usable rear width and 39 feet of clear depth; A continuous access path to the rear homes.
- Main uncertainty
- Sale prices, costs, and the path to separate ownership can change the outcome. Confirm unit-lot subdivision or another legal tenure path before assuming individual sales.
- Next step
- Ask a housing designer to test the site, then review ownership, pricing, and deal terms with appropriate professionals.
Representative site plan
New: 4 homes in a 39×39 ft pack. Drawn on a typical lot — every real lot differs, so this is illustrative, not a site-specific layout.
The program
5 homes — 4 market townhomes in a 39x39 backyard quad.
+4 net new homes per lot (market-rate).
Workbook-baseline economics
You keep the existing home. The acquisition budget applies to the rear development rights; the partnership scenario below assumes contribution recovery and a 50/50 profit split.
- Modeled rear-development-rights budget
- $156K–$197K
- All-in project cost
- $1.98M
- Rear contribution + 50/50 profit-sharing scenario
- $345K–$368K
- Does it pencil?
- Tight
- What to check first
- Parcel-specific inputs
Illustrative 15% developer profit on total cost, conservative through base selling costs. Existing construction financing held fixed; excludes acquisition financing and purchase closing costs. Not an expected offer.
$495K per home
Owner contributes rear development rights at modeled value, receives that contribution back, and splits positive profit 50/50 with the builder. Across conservative and base selling-cost cases; before mortgage payoff, taxes and negotiated waterfall terms.
A 10% market-home price drop erases the profit under conservative selling costs.
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.
Modeled rear-development-rights budget
$156K–$197K
Net sale proceeds ÷ (1 + target return) − costs excluding the existing contribution value. Range uses conservative and base selling costs. The 15% starting target is illustrative; set it to a prospective partner's requirement. Construction financing stays at the model amount; acquisition financing and purchase closing costs need to be deducted separately. Applies only to the rear project; the retained house is excluded. This is a scenario budget, not an appraisal or expected offer.
Where it fits
Neighborhood-residential lots near major transit with at least 49 ft of usable rear width, roughly 100 ft of lot depth, and a clear back yard deep enough for a 39 ft by 39 ft quad behind the existing house.
What must be true
- A transit-served neighborhood-residential lot with a clear rear yard
- At least about 49 feet of usable rear width and 39 feet of clear depth
- A continuous access path to the rear homes
Verify before relying on it
- Surveyed rear-yard clearances and existing-building location
- Trees, access, utilities, drainage, and emergency response
- Townhome sale prices and construction access
Check Backyard quad behind house 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.
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.
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 State HEAR Electrification Rebates
Washington Department of Commerce / local HEAR administrators
Administrator-run rebates for eligible electrification equipment and installation. Measures, amounts, coverage and available funding vary by local administrator.