Land Development and Site Design
What the exam tests
Land development items test zoning compliance, lot yield, grading and drainage, setbacks, easements, and subdivision platting. Expect a buildable-area or impervious-cover calculation.
Regulatory framework
- Zoning sets minimum lot area, width, frontage, setbacks, height, and impervious cover.
- Setbacks are measured from property lines, not street centerlines, unless the ordinance says otherwise.
- Floodplain, wetland, and buffer restrictions can override the base zoning.
- Stormwater detention is sized for increased runoff from developed impervious area.
Grading and platting
Grading balances cut and fill where possible, directs drainage away from structures, and meets ADA grades at accessible routes. A subdivision plat dedicates right-of-way and easements and creates lots by recorded map.
Worked example
A lot is 80 ft wide by 120 ft deep, area 9,600 ft². Required setbacks are 25 ft front, 20 ft rear, and 8 ft each side. Buildable width = 80 - 8 - 8 = 64 ft. Buildable depth = 120 - 25 - 20 = 75 ft. Buildable area = 64 × 75 = 4,800 ft². If maximum impervious cover is 35%, the cap is 0.35 × 9,600 = 3,360 ft², which is more restrictive than the buildable footprint alone.
Traps
- Measuring setbacks from street centerlines.
- Ignoring easements that prohibit structures.
- Forgetting floodplain or buffer restrictions.
- Using gross lot area instead of net buildable area.
- Sizing detention without accounting for release rate.