Accessory Structures in Merced County, CA (2026)
5 rules for unincorporated Merced County, California.
Verified from official government sources
ADU Rules
Unincorporated Merced County allows up to four accessory dwelling units on a single-family parcel: one junior ADU, one attached ADU, one converted ADU, and one detached ADU, under Zoning Code Section 18.62.070. Multi-family parcels get a different formula, capping converted ADUs at 25% of existing units and detached ADUs at eight.
Merced County ADU Type and Number Per Parcel
Some RestrictionsMerced County Zoning Code § 18.62.070
For parcels meeting the requirements of Section 18.62.020 (Applicability), the following type and number of accessory dwelling units (ADUs) may be allowed: A. Parcels with a Single-Family Dwelling. 1. The following ADU types shall be allowed per parcel with an existing or proposed single-family dwelling: a. One junior accessory dwelling unit (JADU); and b. One attached ADU; and c. One converted...
ADU Owner Occupancy
Merced County requires the property owner to live on site, either in a junior accessory dwelling unit (JADU) or in the remaining part of the single-family home, before the county will treat the JADU as compliant. The rule sits in the county's ADU chapter, Section 18.62.100(F), and applies only to unincorporated county parcels.
Merced County JADU Owner-Occupancy Rule
Some RestrictionsMerced County Zoning Code § 18.62.100(F)
F. Owner Occupancy. The owner shall reside on the property in either the newly created JADU or the remaining portion of the single-family dwelling, unless the junior accessory dwelling unit has separate sanitation facilities or if the owner is a governmental agency, land trust, or housing organization.
ADU Rental Restrictions
Unincorporated Merced County bars accessory dwelling units and junior accessory dwelling units from being used as short-term rentals, along with tents, yurts, RVs, and other non-habitable or restricted-use structures, under the Zoning Code's short-term rental standards.
Merced County ADU Short-Term Rental Ban
Heavy RestrictionsMerced County Zoning Code § 18.60.270(C)(2)
2. Short-term rentals shall not be permitted in any non-habitable structures, tent, yurt, recreational vehicle (RV), or any other provision intended for temporary occupancy. Short-term rentals shall not be permitted within additional dwelling units, accessory dwelling units, or in any structures or dwellings with County covenants or agreements restricting their use, including, but not limited t...
Shed & Carport Rules
A detached shed in unincorporated Merced County needs no building permit if it stays under 120 square feet, 12 feet tall, and skips electrical or plumbing; only one such shed is exempt per dwelling. In residential zones, larger sheds still cannot top 600 square feet on a parcel under a quarter acre or exceed 15 feet in height.
Merced County Shed Size and Permit Rules
Some RestrictionsMerced County Code § 16.12.110(B); Zoning Code § 18.32.030(C)(1)
Chapter 16.16 of this title shall not apply to a building designed or constructed as a detached, single story shed for personal use, not exceeding 120 square feet in floor area, not exceeding 12 feet in height, with no electrical and no plumbing (only one such building exempted under this provision will be allowed for each dwelling on a parcel; additional sheds will require a building permit an...
Tiny Homes
Merced County treats tiny homes as single-family dwellings, not accessory structures, and Section 18.12.040 requires them to sit on a permanent foundation system in every standard residential zone. The one exception is the M-H Mobile Home zone, where Section 18.12.040(B)(7) specifically allows a tiny home without a permanent foundation.
Merced County Tiny Home Foundation Rule
Some RestrictionsMerced County Code § 18.12.040(A)(2)(c), (B)(7)
c. Tiny homes shall be considered single-family dwellings and shall be placed on a permanent foundation system. ... 7. M-H Single-Family Mobile Home Residential Zone. Single-family dwellings shall be a mobile/manufactured home with or without a permanent foundation or a tiny home not on a permanent foundation.
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