Before You Build in Modesto, CA: Permit & Rule Checklist (2026)

Modesto generally does not require building permits for standard residential fences 6 feet or under. Permits are required for fences over 6 feet, retaining walls, and fences with electrical components. Fences must comply with zoning setback requirements.

Modesto limits fences to 6 feet in side and rear yards and 3 feet in front yards under MMC Title 10 (Zoning). Fences up to 8 feet may be allowed with a special use permit or as a condition of project approval. No fence may exceed 8 feet.

Modesto follows California Civil Code regarding shared boundary fences. Adjoining property owners share equal responsibility for maintaining boundary fences under CA Civil Code §841. The city does not mediate private fence disputes.

Modesto requires all swimming pools to have safety barriers per California Building Code (CBC) Chapter 31. Pool barriers must be at least 5 feet high with self-closing, self-latching gates. All openings must prevent passage of a 4-inch sphere.

Modesto requires a building permit for all new residential swimming pools, spas, and hot tubs under Title 9 of the Municipal Code, which adopts the California Building Code. Permits are obtained through the Building Safety Division and inspections are mandatory before backfilling or covering work.

Above-ground pools in Modesto must meet the same safety barrier requirements as in-ground pools if they hold 18+ inches of water. Pools with walls at least 48 inches high with lockable ladders may satisfy some barrier requirements.

Modesto enforces California state pool safety regulations including barrier requirements, anti-entrapment drain covers, and the Swimming Pool Safety Act. Building permits with electrical, plumbing, and barrier inspections are required for all new pools.

Modesto allows Accessory Dwelling Units (ADUs) on residential lots per California state law (Government Code §65852.2). ADUs up to 800 sq ft are permitted by right on single-family lots. Larger ADUs up to 1,200 sq ft may be allowed depending on lot size.

Modesto allows garage conversions to ADUs under California state ADU law. Converting a garage to living space requires building permits for electrical, plumbing, insulation, and egress. Replacement parking may not be required per state law.

Modesto's zoning code regulates carports as accessory structures under MMC §§ 10-4.107, 10-4.108, and 10-4.114, imposing minimum setbacks, a one-story height cap, and maximum floor area tied to lot size.

Modesto regulates tiny homes through its Accessory Dwelling Unit ordinance at Modesto Municipal Code 10-4.115, consistent with California Government Code 65852.2. Detached tiny-home ADUs are limited to 800 square feet, 16 feet in height (with state-permitted exceptions), and 4-foot side and rear setbacks. Tiny homes on wheels (THOWs) are not recognized as permanent ADUs.

Modesto allows sheds and small accessory structures in residential zones. Structures under 120 sq ft typically do not require a building permit but must meet setback requirements. Larger structures require permits.

Modesto allows recreational fire pits with restrictions. Fire pits must be at least 15 feet from structures, use clean dry wood or propane/natural gas, and comply with SJVAPCD Check-Before-You-Burn advisories during winter months.

Outdoor burning of trash, yard waste, and debris is prohibited in Modesto. The city is within the San Joaquin Valley Air Basin, which has some of the worst air quality in the nation. The San Joaquin Valley Air Pollution Control District (SJVAPCD) regulates all burning.

Modesto generally allows removal of privately owned trees on private property without a permit, unless the tree is in a planned development or specific plan area. City-owned street trees require city authorization for removal. Heritage or significant trees may have protections.

Modesto requires property owners to maintain trees so they do not obstruct sidewalks (8 ft clearance), streets (14 ft clearance), or block sight lines at intersections. City-maintained street trees may only be trimmed by city crews or approved contractors.

Modesto enforces water conservation measures year-round, with additional restrictions during drought conditions. Outdoor watering is limited to specific days and times. The city is served by a combination of groundwater and Modesto Irrigation District surface water.