Site Plan & As-Built Drawing Cost in 2026 (What You Need)
In 2026, a site plan typically costs $100 to $1,500, and as-built drawings run $700 to $1,300. A site plan shows how your project sits on the lot; as-builts document a building exactly as it currently exists. You often need one or both for permits, additions, ADUs, and remodels — and the price depends on your lot's complexity and how detailed the drawings must be.
What is a site plan?
A site plan is a scaled, bird's-eye drawing of your property. It shows the lot boundaries and where everything sits within them: the house, driveways, walkways, decks, fences, trees, and utilities. It also marks setbacks — the required distances from your structures to the property lines.
Permit offices use site plans to confirm your project fits local zoning rules before they approve it.
Typical cost: $100 to $1,500. A simple site plan for a flat, rectangular lot sits at the low end. A large or irregular lot with many features, slopes, or utility details costs more.
What are as-built drawings?
As-built drawings document a structure exactly as it exists today — accurate measurements of walls, rooms, windows, doors, ceiling heights, and often mechanical and structural elements. They're the "before" picture a designer needs to plan changes.
Typical cost: $700 to $1,300. The price depends on the building's size and complexity and how much field measuring is required.
When do you need each one?
| Situation | Site plan | As-built drawings |
|---|---|---|
| Building an addition | Usually | Yes — to connect to the existing home |
| Adding an ADU or garage | Yes | Sometimes (for conversions) |
| Major remodel | Sometimes | Yes — to plan around existing conditions |
| New home on a lot | Yes | No (nothing exists yet) |
| Adding a deck, pool, or fence | Often | No |
| Selling / refinancing | Sometimes | Sometimes |
In short: site plans answer "where does it go on the lot?" and as-builts answer "what's already here?" Additions and ADU conversions frequently need both — the site plan for the permit, the as-builts so the designer knows what they're building onto.
Related drawing costs
If you're pricing out a project, these often come up alongside site plans and as-builts.
| Document | Typical cost |
|---|---|
| Site plan | $100–$1,500 |
| As-built drawings | $700–$1,300 |
| Altering existing plans | $150–$2,500 |
| Home addition / extension plans | $1,200–$5,000 |
| CAD drawings (per sheet) | $35–$180 |
What drives the price
For site plans:
- Lot size and shape. Large or irregular lots take more work to draw accurately.
- Level of detail required. Some permit offices want extensive utility, drainage, and grading information; others accept a simple diagram.
- Existing survey. If you have a recent property survey, the designer can work from it and charge less.
- Slope and features. Trees, easements, and grade changes all add time.
For as-builts:
- Building size. More rooms and levels mean more field measuring.
- Complexity. Unusual layouts, hidden structure, and mechanical systems add hours.
- Accuracy needed. Precise structural as-builts cost more than a basic floor-plan measure-up.
How to save
- Use an existing survey. A recent survey can dramatically cut site-plan cost — the designer isn't starting from scratch.
- Provide any documents you have. Old plans, permits, or appraisals give the drafter a head start on as-builts.
- Bundle the work. If a designer is already drawing your addition, having them handle the site plan and as-builts together is often cheaper than hiring separately.
- Ask your permit office what level of detail they actually require, so you don't pay for more than you need.
You can compare vetted local designers and drafters who handle site plans and as-builts, which makes it easy to find someone who knows your jurisdiction's specific requirements.
A quick note on surveys
A site plan is not the same as a boundary survey, which is prepared by a licensed land surveyor and legally establishes your property lines. Some permit offices require a survey as the basis for the site plan. If your lot lines are unclear or disputed, budget for a survey separately — it's a different service from the design drawings above.
Bottom line: expect $100 to $1,500 for a site plan and $700 to $1,300 for as-built drawings, and check with your permit office on required detail before ordering either.