Showing ordinances that apply to Loma Mar, CA
Loma Mar is an unincorporated community (population 134) in San Mateo County, California. Because Loma Mar is not an incorporated city, it does not have its own municipal code. Instead, San Mateo County ordinances apply directly to properties here. The lot coverage limits rules below are the ones that govern your area.
Lot coverage limits in unincorporated San Mateo County range from 25% to 50% depending on paired S-District and zoning. Typical R-1 with S-100-series: 40-45% maximum coverage. Hillside (RH): 25-30% with additional slope-based reductions. Coverage includes the footprint of all buildings and covered structures; impervious surface limits (including driveways and patios) separately apply under the NPDES Stormwater requirements (C.3) for projects creating or replacing 2,500+ sq ft of impervious surface.
Lot coverage, defined under County Zoning Regulations as the horizontal area of a lot covered by buildings including covered porches/decks and attached structures, is capped by the S-District standard. Typical values: S-100 (5,000 sq ft R-1): 45%; S-101 (7,500 sq ft R-1): 40%; S-17 (20,000 sq ft R-1 or RH): 30%; agricultural: 10-15%. Impervious surface (a separate calculation) includes buildings, driveways, patios, pools, and compacted gravel — projects creating or replacing 2,500+ sq ft of impervious surface trigger NPDES C.3 stormwater treatment requirements under the Bay Area Regional Municipal Stormwater Permit (Order R2-2022-0018). Permeable pavers may receive partial credit (typically 50%) toward impervious surface calculations but count fully toward lot coverage if they form a structural surface. Hillside lots with slopes over 20% have reduced allowed coverage. Exceeding coverage requires a variance through Planning Commission. ADUs under 800 sq ft are exempt from lot coverage calculations under state law.
Exceeding lot coverage: building permit denial, required redesign. Completed violations: correction (removal of excess structure) or variance with public hearing. Fines $200-$1,000 per §1.04. Impervious exceedance without C.3 treatment: stormwater violation $500-$10,000.
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