An old survey is often one of the most valuable documents a homeowner has, and in many cases it can be used for a building permit, either directly or as the base for a new site plan. Whether yours still works depends on what has changed since it was drawn and what your permit office asks for.
Quick answer: Usually yes, as the source for a site plan. An old survey still shows the legal boundary if the lot has not been split, combined or re-platted and the corners are intact. Add the current buildings and the proposed work, note the survey date as the source, and check whether your county requires a survey under a certain age.
Why an old survey is still useful
Property lines rarely move. A boundary established by a licensed surveyor ten or thirty years ago is normally still the boundary today. What changes is what sits on the lot: a new patio, a removed shed, an addition. That is why permit offices often accept a site plan drawn on an old survey, with today’s buildings and the new project added. Our pillar guide on site plan vs survey explains how the two documents work together.
When an old survey still works
- The lot has not been split, combined or adjusted since the survey date.
- The survey shows bearings, distances and corner markers, not just a sketch of the house.
- The corner markers are still in place, or can be found.
- Your permit office does not set a maximum survey age for your project type.
- The project is not so close to a line that a small discrepancy would matter.
When you may need a new survey
- The lot has changed through a split, lot line adjustment, road widening or new easement.
- The county requires a recent survey, which some do for new homes or major additions.
- Corner markers are missing and the work will be near a line.
- The old document is not a boundary survey but a mortgage or location survey with a “not for construction” note; see our comparison of a mortgage survey vs boundary survey.
- A neighbour disputes the line, or a fence clearly sits in the wrong place.
How to tell what kind of survey you have
Look at the drawing itself:
| You see | It is probably |
|---|---|
| Bearings such as N 89°12′ E, distances, corner monuments, seal and signature | A boundary survey |
| House outline with distances to lines, “not for fence construction” note | A mortgage or location survey |
| Contour lines and spot elevations | A topographic survey |
| Many lots with lot numbers and street names | A recorded subdivision plat |
Our guide to the types of land surveys describes each in more detail.
Turning an old survey into a permit site plan
- Get a clean copy. Scan the original at high resolution, or request a copy from the county recorder or the surveying firm.
- Check the scale. Old surveys are often at 1 inch = 20 or 30 feet. Confirm with a known dimension before measuring.
- Update existing conditions. Add buildings, patios and driveways built since the survey; remove anything demolished.
- Add the proposed work, shaded and labelled as new, with distances to each line.
- Add a title block naming the survey (surveyor and date) as the source and stating that the site plan is not a new survey.
Many people send their old survey to a drafting service to do this cleanly. When we prepare a site plan from your survey, the original surveyor and date are cited on the sheet so the reviewer can trace the boundary.
What reviewers check on an old survey
Reviewers mainly want to know whether the survey still represents the lot. Expect questions if the lot area or frontage differs from the county record, if there are buildings on the ground that are missing from the drawing, or if the survey shows an older road edge where the right-of-way has since been widened. Answering these upfront in the title block or a note saves a correction round.
Old survey vs new survey: a quick decision
Ask three questions. Has anything changed about the lot itself since the survey? Is your project within a couple of feet of a setback or easement? Does your permit office, lender or title company require a recent survey? If the answer to all three is no, an old survey used as the base for a site plan is almost always the faster and cheaper route. If any answer is yes, talk to a surveyor about an update or a new survey before you design around the old one.
Where to find an old survey
- Your closing documents from the purchase.
- Your lender or title company.
- The county recorder or register of deeds (for recorded surveys and plats).
- The surveying firm named on a neighbour’s survey, which may have records for your lot too.
- Previous owners, or the builder for newer homes.
If you can’t find any survey, a plat plus the county parcel map is often enough for a site plan. Our guide on how to find your property lines shows how to check them on the ground.
Frequently asked questions
How old is too old for a survey?
There is no universal limit. A survey does not expire, but some permit offices, lenders and title companies require one prepared or updated within a set period. Check the requirement for your project.
Can a surveyor update an old survey instead of starting over?
Often yes. Many surveyors offer an update or re-certification, which can be quicker when their firm prepared the original.
My old survey has a “not for fence construction” note. Can I use it?
It can be a source for a site plan, but it is not a boundary survey. Don’t build on the line based on it.
What if the old survey doesn’t match the county GIS map?
The survey is normally more reliable. GIS parcel lines are approximate and can be off by several feet.
