Converting an existing garage (attached or detached) into a permitted ADU — the cheapest entry point because the foundation, walls, and roof already exist.
California state law (since 2020) requires cities to allow garage conversions on every single-family lot, with no parking-replacement requirement. Typical 2026 cost: $36k-$96k in LA. Common pitfalls: raising the slab elevation, adding insulation to Title 24, adding egress windows, adding plumbing rough-in.
Part of the BackyardADU California ADU Glossary — plain-English definitions of the regulatory, construction, and financing terms you'll encounter during a California ADU project.