Survey Types
As-Built Survey
A record of what actually got built, which is rarely identical to what was drawn.
An as-built survey measures constructed improvements in their final position and compares them against the approved design. Sometimes it is called a record survey or record drawing. Cities, utility districts and owners all use it to confirm that what exists matches what was permitted.
Why the field never matches the plan exactly
Field conditions change things. A sewer line shifts three feet to miss a rock shelf. A building pad ends up a tenth high. A curb radius gets adjusted because a truck could not make the turn. None of that is necessarily wrong, but somebody has to record it, because the next person who digs on that site will be working from these drawings.
When you need one
- The city or utility will not close out your permit without it
- Public infrastructure is being dedicated and the accepting agency requires record drawings
- A lender or owner wants verification before final payment
- You are buying a property and want to confirm improvements sit where they should
- An addition is planned and the design team needs accurate existing conditions
- Something looks like it may encroach on an easement or a setback
What gets documented
Scope varies with what the receiving agency asks for. Typical items include building footprints and finished floor elevations, pavement and curb locations, storm and sanitary structures with rim and invert elevations, water valves and hydrants, retaining walls, and site drainage features.
For underground utilities, timing is everything. If the surveyor measures before backfill, the data is accurate and cheap to collect. If they show up after everything is covered, the work becomes a guessing exercise supplemented by locating equipment, and the results are weaker.
Get utilities shot before they are buried. This is the single most common as-built mistake and it is entirely avoidable. Put the survey visit into the construction schedule rather than treating it as a closeout task.
As-built versus a boundary survey
They answer different questions. A boundary survey establishes where the property lines are. An as-built documents where the improvements are. Many as-built drawings show the boundary for context, but showing a line and legally establishing it are not the same thing. If you need the line defended, order the boundary survey.
Setback and easement verification
One practical use of an as-built is confirming a structure sits inside its required setbacks and outside any easements. Finding out a garage corner sits eighteen inches into a utility easement is unwelcome news, but finding it out at closeout is considerably better than finding out years later when the utility needs access and has every right to take it.