11/10/2025 9:07 AM (PST)

It really depends on the type of ADU you’re building and how smooth the permit process goes. When I built mine, it took about 7 months total — 2 months for permits and around 5 months for construction. Some prefab units go faster, maybe 3–4 months. If you’re going for a custom design, expect it to take longer because of plan checks and possible city revisions. I used https://www.aduscale.com/adu-construction-in-los-angeles, to estimate my timeline and get guidance, and they were pretty accurate about each stage. It helped me plan around inspections and avoid delays with contractors.