Twain Harte, CA Building Setbacks & Zoning: Lot Coverage Limits (2026)

Rather than a single percentage lot-coverage cap, Tuolumne County regulates building intensity through a floor area ratio (FAR) set per district in Chapter 17.12. In the Single-Family (R-1), Medium Density (R-2), and Multiple-Family (R-3) districts, the maximum FAR is 0.5 on conforming-size parcels; smaller lots get a higher FAR of 0.6 (single-story) or 0.75 (multi-story) to allow reasonable use. The Residential Estate districts RE-1, RE-2, and RE-3 also cap FAR at 0.5, while the larger-lot RE-5 and RE-10 districts cap FAR at 0.2 to preserve open space. Density bonuses for affordable housing and allowances for accessory dwelling units can add coverage above these base figures under state law. For garages used as a primary parcel use, Table 17.12.1 limits building coverage to 25 percent of the parcel or 4,000 square feet, whichever is less. Multifamily and dwelling-group projects must also reserve site area and green space: every unit needs a minimum 2,900 square feet of site area, and at least 15 percent of the site (minimum 200 square feet) must be set aside as green or recreation space (Chapter 17.22.030.I). Minimum parcel sizes (for example, 7,260 sq ft in R-1) also constrain how much can be built.