Construction
2 min readWhat Is an As-Built Survey?
Design drawings show intent. An as-built survey records reality: the measured positions and elevations of what was actually constructed. It's how a project proves the pipe is where the drawing says, the slab is at grade, and the works meet the approvals they were built under.
What gets recorded
- —Underground utilities — measured before backfill hides them forever
- —Finished surfaces, slabs and structures against design grade
- —Roadworks: centreline, kerbs, structures and drainage
- —Site servicing for municipal acceptance packages
- —Any deviation from design, documented rather than discovered later
Timing is everything
The most valuable as-built shots happen during construction, not after. A water service is a thirty-second measurement while the trench is open — and an expensive investigation five years later. Good projects build as-built pickups into the construction sequence, especially for anything that gets buried or encased.
Who needs it
Municipalities typically require as-built records before accepting infrastructure. Engineers need them to certify works. Owners inherit them as the permanent record of their asset — the drawing the next renovation, repair or excavation will rely on. And contractors use them as protection: measured proof of conforming work at the moment it was completed.
The deliverable
As-built deliverables usually mirror the design package: red-line or revised CAD drawings, PDF record sets, and structured data where the owner maintains GIS records. The best practice is simple — record it in the same coordinate system the project was designed and laid out in, so the whole lifecycle of the site shares one spatial story.
Related service
As-Built Surveys
Record what was actually built — surfaces, structures and services.