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San Diego ADU feasibility · see what fits your lot

A LOT
MORE.

Explore an ADU on your lot in 3D.

See what could fit, compare estimated build costs, and explore rental potential.

Free to explore. No account needed for your first address.

Just looking? See a sample result
Est. rent
$2,754/mo
Simple payback
11.3 yrs
Build cost
$231k–$289k
Coyote Brush Court demo, San Diego · market rent · open it in 3D
ILLUSTRATIVE CONCEPT · SCALE 1:100LOT — 001 / ORTHO 3D
Illustrative miniature lot with an existing house and an orange backyard home
A little more possibility
POINT 01 / 0324′ × 25′ footprint · 1 bed

Proposed 600 sq ft ADU. Positioned in the rear yard envelope with full-height southern glazing and private deck access.

Backyard home conceptIllustrative parcel model
Also on AndroidGet it on Google Play

01INSIDE THE STUDIO

See the studio.
Try the same lot.

Explore the same 600 sq ft Coyote Brush Court demo shown above, with the $2,754/mo market rent assumption.

Try the Coyote Brush Court demo
Studio previewOak Street demo, Seattle
Oak Street demo in the LotFoundry 3D studio, showing an existing home and a proposed backyard home
FOOTPRINT
ROOF PROFILE
MODELED COVERAGE32% of lot
EST. BUILD BAND$231k–$289k
EST. MARKET RENT$2,754/mo
Seattle Studio preview shown. Open the Coyote Brush Court demo to explore San Diego assumptions.
  1. 01

    Place a backyard home.

    Explore size, roof, and placement alongside your existing home and modeled setbacks.

  2. 02

    Compare the estimates.

    See build costs, rental potential, and payback with the assumptions behind them.

    See the demo numbers
  3. 03

    Plan your next questions.

    Review what needs local confirmation and what the complete certificate includes.

    See what’s included

What would you make room for?

A 600 sq ft, one-bedroom concept. Keep the people you love nearby, with a little more independence for everyone.

02THE DEMO ESTIMATES

Build costs.
Rental potential.

Change the demo’s rent assumption
to see how the estimate responds.

COYOTE BRUSH COURT DEMO, SAN DIEGO · 600 SQ FT · 1 BED CONCEPT

Estimated build cost

$231k–$289kOne-time project estimate

Estimated rental income

$2,754/moBefore expenses and financing

Estimated simple payback

11.3yearsBased on operating income
ANNUAL OPERATING INCOME$22,307/yr
NET OPERATING MARGIN67.5%
MODELED EXPENSE ALLOWANCE32.5% of gross
What’s behind these numbers?

The curated Coyote Brush Court demo in San Diego, calculated by the studio engine: 600 sq ft, cedar finish, shed roof, openings included. Base construction is $340/sq ft, with an 18% soft-cost allowance. Operating expenses use 32.5% of gross rent; estimated annual net operating income is $22,307 before financing and income tax. Simple payback uses the central project estimate divided by this operating income. Rent bands start from HUD's FY2026 Fair Market Rent for a one-bedroom in San Diego County ($2,459/mo), plus the studio's standard 12% and 25% spreads. The lot follows San Diego's RS-1-7 minimums; the address is fictional, and coverage is modeled at 60% because the city limits floor area (0.60 FAR), not flat-lot coverage. Artwork is illustrative.

Explore your own numbers

Calculated with the Studio engine. Compare three rent assumptions before planning your next step.

03WHAT’S INCLUDED

Explore for free.
Prepare your brief.

Take a clear project brief to your partner, builder, or lender. The Certificate of Feasibility helps you test financing assumptions, surface site questions, and compare construction scopes.

Explore in the studioFree
3D layout exploration and an estimated monthly rent range. Your first address needs no account.
Certificate of Feasibility$29 one-time
A property-specific packet: build costs, net income, payback, financing scenarios, a fee and permit audit for its size, and a bid-leveling checklist for three builders. Print or save as PDF, export CSV, or share a permanent link.
  • Test monthly cash flow. Compare a HELOC and a construction-to-permanent loan after the operating allowance and loan payments.
  • Spot questions before requesting quotes. Review modeled setbacks, coverage, utility scope, and fee checks.
  • Give builders the same brief. Bring a 12-item scope checklist and a printable PDF to your next conversation.
LotFoundrySAMPLE REPORT
02 / 03

MARKET DEMO ASSUMPTIONS

A clearer
financial picture.

Construction base
$204,000
Roof premium
$0
Openings allowance
$9,000
Regional hard-cost adjustment
$0
Soft-cost allowance
$38,340
Estimated build cost
$231,000–$289,000
Estimated monthly rent
$2,754
Annual operating income
$22,307
Simple payback
11.3 years

Same 600 sq ft Coyote Brush Court demo, San Diego, and selected rent assumption as above. The full sample adds the financing comparison.

PRE-CONSTRUCTION FEASIBILITY BRIEF

Sample Certificate of Feasibility summary. Create yours in the studio.

Start with my lot

The complete certificate is an optional one-time purchase. Review it in the studio before checkout.

04BEFORE YOU START

Good questions.
Straight answers.

A little more help
What is a backyard home?

An accessory dwelling unit, or ADU, is a smaller home on the same property as a primary residence. It can offer independent living space for family or potential rental income, subject to local requirements.

Can I check my address?

Yes. Your first address lookup needs no account — enter it above and the studio opens on your own lot. Create a free account to look up more. Available parcel and market detail varies by location, and the studio identifies its assumptions and anything missing. Seattle, Portland, Austin, and San Diego demo lots are always open.

How are the estimates calculated?

The studio combines the proposed size and finish with construction assumptions, rent inputs, and operating expenses. Live-address results show their market basis when available. Demo figures use curated assumptions, and all results need local confirmation.

Does this mean I can build?

No. LotFoundry helps you explore an early concept. It does not grant a permit or guarantee a buildable design. A local professional and your jurisdiction must confirm property conditions and applicable requirements.

What is free, and what costs extra?

Exploring the 3D concept and monthly rent range is free. The complete Certificate of Feasibility is a one-time $29 purchase. You can review what is included before checkout.

A LITTLE LAND. A LOT OF POSSIBILITY.

It starts with
your address.

See what more could look like on your lot.

Free to explore. No account needed for your first address.

YOUR NEXT CHAPTER / LOTFOUNDRY