CA · City hub

San Diego — modular, container,
and tiny homes in California.

San Diego runs the country's most permissive ADU framework via the city's Bonus ADU program. Modular, panelized, and expandable-container paths all clear here — and the JADU + ADU combo unlocks two additional units on most single-family lots.

What the market looks like

San Diego in 2026.

San Diego's Bonus ADU program (adopted 2020, refined 2023) allows an additional ADU for each deed-restricted affordable unit provided on the same lot, on top of the state-mandated one detached ADU + one JADU allowed under California SB 9 and AB 68/881. Coastal zone parcels carry an additional Coastal Commission review layer. HUD Small-Area FMR data covers every ZIP in San Diego County. Mediterranean climate reduces the HVAC spec burden, but wildfire-urban-interface parcels in East County require Class-A roof assemblies, ember-resistant vents, and 100 ft of defensible space. Modular and factory-panelized products dominate permitted ADU builds because they compress the on-site construction window in a market where labor is scarce.

Guides

Guides for San Diego.

Guide

Expandable container homes in San Diego

Why the expandable form factor keeps showing up in San Diego ADU permits — affordability, install speed, and STR yield.

Read → Guide

California backyard size benchmarks — 2026

What San Diego County lot sizes mean for stacking a JADU + detached ADU + Bonus ADU on one parcel.

Read → Guide

Affordable container homes for California

The container-home path across California, including the San Diego permit specifics.

Read →

Find a builder

Verified builders in California.

ADU match

Find a verified ADU builder in California.

License-verified, bond-verified, complaint-record-checked. One match within 24 hours. Free for buyers.

Get matched → Directory

Top modular home builders in California — 2026.

The ranked builder directory PERCH publishes for California, with product classes, code paths, and price bands.

Read the directory →

Financing

Financing paths in California.

CalHFA MyHome and ADU Grant Program (up to $40,000 for pre-development costs) are the most common down-payment assistance paths for owner-occupied ADUs.
FHA 203(k), Fannie Mae HomeStyle, and Freddie Mac CHOICERenovation loans finance detached ADUs on existing San Diego single-family lots.
San Diego Housing Commission offers ADU financing for deed-restricted affordable ADUs under the Bonus ADU program.
Local credit unions (San Diego County Credit Union, Mission Fed) offer construction-to-permanent loans tuned to the California ADU market.
Chattel loans finance manufactured HUD-code units placed in San Diego County registered communities.

Authoritative sources

CalHFA ADU Grant Program HUD California Homeownership City of San Diego Development Services — ADU

Ready to move

Ready to buy or list in San Diego?

Buyer

Take the Find Yours quiz.

Answer six questions and PERCH matches you to the housing typology — modular, manufactured, tiny, ADU, or container — that fits San Diego and your budget.

Start the quiz → Seller / Investor