What Is a Site Plan?
A site plan is a drawing of a property that shows existing and proposed buildings, setbacks, driveways, utilities, grading and drainage. Simple plot plans may be drawn by owners, but engineered site plans are prepared and sealed by a civil engineer.
What a site plan shows
At minimum: property lines and dimensions, the footprint of existing and proposed structures, distances to property lines (setbacks), driveways and parking, easements, and the north arrow and scale. Engineered site plans add existing and proposed contours or spot elevations, drainage paths, utilities (water, sewer or septic, gas, electric), erosion and sediment control, and stormwater facilities.
Commercial site plans add parking counts and dimensions, ADA accessible routes, landscaping, lighting, fire access, traffic circulation and detailed utility and stormwater designs.
When you need one
Most building departments require a site or plot plan for new houses, additions, accessory dwelling units, pools, large decks and accessory buildings so they can check zoning setbacks, lot coverage and drainage. Planning departments require full site plans for commercial development, subdivisions and many multifamily projects.
Whether the plan must be sealed by an engineer depends on the jurisdiction and the work. Grading, stormwater and utility design typically require a PE.
How it gets made
The process usually starts with a boundary and topographic survey by a licensed surveyor. The civil engineer then designs the layout, grading and utilities on that base and prepares the permit drawings. For larger projects the plan goes through planning, engineering, fire and utility reviews before approval.
Revisions are normal. Reviewers often ask for added dimensions, utility details or drainage information, and the engineer responds with revised sheets and a comment response letter. Once approved, the site plan becomes the basis for construction stakeout and inspections, so changes in the field usually need the engineer's and the reviewer's agreement.
Frequently asked questions
Can I draw my own site plan?
Many jurisdictions accept owner-drawn plot plans for simple projects. Engineered elements such as grading and drainage usually require a professional.
Is a survey the same as a site plan?
No. A survey shows existing conditions and boundaries. A site plan shows what will be built.
How long does site plan approval take?
Residential plans may be reviewed in days to weeks; commercial site plans can take months depending on the jurisdiction and public hearings.
Sources
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