R-1 (or equivalent RS-1, SF, SFR) is the most common residential zoning classification in the US. Typical permitted uses: single-family detached dwelling, accessory dwelling unit (ADU — increasingly by-right in many states since 2020), home occupation/office, gardening, one accessory structure (garage, shed). Conditional/special uses: daycare (6+ children), bed and breakfast, religious assembly, public utility. Prohibited: multi-family, commercial, industrial. Typical dimensional requirements: minimum lot size 5,000-10,000 sf (varies greatly by municipality), maximum height 35 feet / 2.5 stories, front setback 15-30 feet, side setback 5-10 feet, rear setback 15-25 feet, maximum lot coverage 30-50%, maximum FAR 0.4-0.6. Parking: 2 spaces per dwelling unit (1 covered). Variances require public hearing — typically Board of Adjustment. Rezoning requires legislative approval — City Council. ADU regulations vary dramatically by jurisdiction — check local code.