Quick answer
A site plan (also called a plot plan) is a scaled, top-down drawing of your property showing the lot lines, existing and proposed buildings, their distances from the property lines, driveways, utilities and drainage. Building departments use it to check zoning rules such as setbacks and lot coverage before they review the building itself.
Almost every permit for new construction, an addition, a garage, an ADU, a pool or a deck asks for a site plan. It is often the first sheet the reviewer opens, and an incomplete one can stop a permit at intake.
Site plan vs survey: what is the difference?
A survey is prepared by a licensed land surveyor and legally establishes where your property lines and existing features are. A site plan uses that information to show what you plan to build and where. Many departments accept a site plan drawn on top of an existing survey. Some require a new survey for new homes, or when a building will be close to a property line.
Site plan checklist
- North arrow, scale and the property address or parcel number
- All property lines with dimensions, and the lot area
- Existing buildings and the new work, clearly labeled
- Setback distances from each building to every property line
- Lot coverage and impervious area calculations where the zoning code limits them
- Driveways, parking spaces, walkways, patios and pools
- Easements, rights-of-way and any recorded restrictions
- Utilities: water, sewer or septic and well, electric and gas routes
- Drainage direction, and grading where the ground is being changed
- Trees, slopes, creeks, flood zones or wetlands where the department asks for them
Example: a backyard ADU site plan
For a detached ADU, the site plan would show the lot, the main house, the new unit with its dimensions, the distances from the ADU to the rear and side lot lines and to the main house, the path from the street to the ADU’s entrance, any parking required, and the new sewer, water and power routes from the main house. Read more in our ADU engineering guide.
Common site plan mistakes
- No scale, or a scale that does not match the dimensions
- Setbacks shown to the fence instead of the property line
- Missing easements, which can block a structure from being built where planned
- No lot coverage calculation where zoning limits it
- A satellite image instead of a measured drawing
How to get a site plan
You can draw a simple site plan yourself from your survey for small projects. For new homes, ADUs, additions near the property line and anything involving grading or drainage, a professionally prepared site plan avoids returns. Our site plan service prepares scaled, permit-ready site plans from your survey or recorded plat, and our civil engineering team handles grading and drainage plans.
What to send us
- Your survey or recorded plat (a photo or PDF is fine)
- A sketch of what you plan to build and roughly where
- The property address
- Any comments from the building or planning department
Common questions
Can I draw my own site plan?
For small projects, many departments accept a homeowner-drawn site plan based on a survey, as long as it is to scale and shows all required distances.
Do I need a surveyor for a site plan?
Not always. You need reliable property line information, which usually comes from an existing survey or plat. New homes and work near property lines often require a new survey.
What scale should a site plan be?
Common scales are 1 inch equals 10, 20 or 30 feet, chosen so the whole lot fits on the sheet while staying readable.
Is a plot plan the same as a site plan?
Yes. Different departments use the two terms for the same drawing.