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Permit guides
ADU Permits in Merced: a Homeowner's Guide
Merced offers three free pre-approved ADU designs and a fully online submittal portal — plus impact fees that scale with the size of your main house.
Last updated October 2026. Rules change; always confirm current requirements with the city before you build.
Who handles your permit
The City of Merced Development Services Department handles ADU permits, and submittal runs through the city's Civic Access portal — you upload plans there, staff invoices fees in the portal, and the permit doesn't issue until fees are paid. For resubmittals, the Engineering Department's published process has applicants email encroachmentpermit@cityofmerced.org with the permit number in the subject line; full documents only, no individual pages.
What you can build
3 free plansPre-approved sets: 498, 749, and 1,190 sq ft — no cost
Civic AccessThe city's online portal for submittal and fee payment
Proportional feesADU impact fees proportional to the primary dwelling's size
Bear CreekFlood zones along Bear Creek affect siting and elevation
1,200 sq ftDetached ADU max under state law
60 daysState-required decision on a complete application
Merced's Pre-Approved ADU Program
Merced's Pre-Approved ADU Program provides three pre-reviewed plan sets for detached ADUs — 498, 749, and 1,190 square feet — at no cost, plus an ADU How-To Guide and a Pre-Approved ADU Design Workbook. The sets meet height, size, foundation, and architecture standards up front, which is where most of the review time goes.
Two things to know: the pre-approved sets don't include separate submittals for trusses, solar, or fire sprinklers (if required) — those are on you — and each application still needs a program cover sheet, a site plan, a soils moisture and compaction report, a waiver and release form, and energy compliance.
What goes into the submittal
- Building permit application filed through the Civic Access portal, with the program cover sheet attached for pre-approved plans.
- Site plan showing the unit's placement, setbacks, easements, and utility connections.
- Soils moisture and compaction report (required prior to rebar) — line this up early.
- Energy compliance, plumbing, HVAC, and electrical plans — the pre-approved sheets cover the base design, not your site's MEP.
- Fee payment in the portal — Merced's ADU impact fees are assessed proportional to the primary dwelling's size, and the permit doesn't issue until the invoice is paid.
Where applications usually get stuck
- Bear Creek flood zones. Floodplain areas along Bear Creek change siting, elevation, and foundation details — confirm the zone before choosing a plan.
- Deferred submittals. Trusses, solar, and sprinklers aren't in the free plan sets — owners who forget them stall at framing inspection.
- Soils reports. The moisture/compaction report is easy to overlook until rebar is scheduled — order it with the survey.
- Portal invoice timing. Fees are invoiced after review and the permit waits on payment — budget the full proportional impact fee, not just plan check.
- Ag and growth edges. Merced's expansion areas mix new subdivisions with working farmland — buffers and drainage easements show up on fringe lots.
Not sure where to start? That's the part we do. We look at your property, map the requirements, coordinate the plans and specialists, and manage the submittal and corrections — one point of contact.