Quick Verdict
As-built grades are a survey of the finished ground that documents exactly how a site was built, compared against the approved design. Final grade certification is the signed confirmation, usually from a surveyor or engineer, that the site was graded to plan within tolerance. In Oregon, jurisdictions and inspectors often require this before they sign off on a project, release a permit, or let paving and building proceed. As-built grades protect everyone: they prove drainage flows where it should, that pads sit at the right elevation, and that the dirt you paid for landed where the plan called for it. Skipping certification can stall a project at inspection.
What As-Built Grades Are
Every graded site starts as a design: a set of drawings showing target elevations, slopes, and drainage. As-built grades are the reality check. After the earthwork is done, a surveyor measures the actual finished elevations across the site and produces a record of what was really built.
That record is compared to the design. Where they match within tolerance, the grade is accepted. Where they do not, the contractor fixes the out-of-spec areas before anything gets buried or paved over. Grade certification is the formal statement that the as-built matches the approved plan.
Why Certification Matters
Final grade certification exists because grading mistakes are expensive to find later. A pad built two inches low, a drainage swale that runs the wrong way, or a slope that ponds water becomes a real problem once a building or parking lot sits on top of it.
- Inspection sign-off. Many Oregon jurisdictions require certified grades before releasing the next phase.
- Drainage proof. Certification confirms water leaves the site as designed, which matters for stormwater compliance.
- Protects the owner. A documented, verified grade means the owner paid for and received the right work.
- Protects the contractor. A signed as-built is proof the job was built to plan if a dispute comes up later.
- Feeds the record set. As-builts become part of the permanent project documentation.
The accuracy that makes certification easy usually comes from grading with precise methods in the first place, like GPS machine-control grading for the bulk shaping and laser grading and fine grading for the finish.
How the Process Works
Getting to a certified final grade runs in a predictable order:
- Grade to the design using stakes, laser, or GPS control.
- Survey the finished surface at enough points to capture the real elevations.
- Compare to design and flag any areas outside tolerance.
- Correct out-of-spec areas with additional cut or fill.
- Re-survey the corrected areas to confirm they now match.
- Certify and document with a signed as-built for the inspector and the record set.
The tighter the tolerance a project demands, the more the front-end grading method matters. Loose stake-and-check grading may need several correction passes to certify; precise machine control often certifies with little rework.
Tolerance and What Gets Checked
Certification is not about perfection to the millimeter; it is about being within an allowed tolerance for the surface type.
| Surface Type | Typical Certification Focus |
|---|---|
| Building pad | Elevation and flatness within tolerance |
| Parking and drive lanes | Slope for drainage, no ponding |
| Drainage swales | Continuous fall to the outlet |
| Detention and stormwater | Volume and invert elevations |
| Finished landscape areas | Positive drainage away from structures |
How the As-Built Survey Is Captured
The as-built is only as trustworthy as the survey behind it, so the capture method matters. On most Oregon sites a surveyor walks the finished grade with a GPS rover or shoots it with a total station, taking enough points to describe every slope break, swale, pad corner, and drainage invert. Larger or open sites increasingly use drone photogrammetry to build a dense surface model in a fraction of the time. The denser and more accurate the points, the more confident the comparison against the design.
- GPS rover: fast and flexible, good for most open grades
- Total station: high precision where line of sight allows, common for tight tolerances
- Drone photogrammetry: dense coverage of large areas quickly
- Level and rod: simple spot checks and small sites
The same GPS control that guides the grader can feed the as-built, which is one reason machine-control grading and clean certification go together. Capturing enough points is what separates a defensible as-built from a handful of readings that miss the low spot where water ponds.
Common Corrections Before a Grade Certifies
When an as-built comes back out of tolerance, the fixes are usually small but specific, and catching them before paving or building is the whole point of certifying. The recurring culprits in Oregon:
- A drainage swale that lost its continuous fall and now holds water
- A pad set an inch or two off design elevation
- A finished area that sheds toward a structure instead of away
- A detention basin with the wrong invert or volume
- Compaction or settlement that dropped a corner after grading
Each one is corrected with a targeted cut or fill, then re-surveyed to confirm it now matches. The more accurately the site was graded up front, the shorter this list -- which is why precise methods pay for themselves at certification.
Oregon-Specific Notes
Oregon's wet winters make drainage the star of grade certification. A site that certifies clean in summer still has to move water through the rainy season, so certifiers pay close attention to positive drainage and swale fall. Willamette Valley clay compounds this because water sits, so even small grade errors show up as standing water. Certification also ties into stormwater and erosion permit close-out on regulated sites. For how certification fits at the end of a full earthwork sequence, the Oregon excavation contractor guide covers the project flow.
What It Costs
As-built survey and certification is priced by site size, the number of points needed, and how many correction and re-survey rounds the grade requires.
| Item | Baseline Range |
|---|---|
| Grading / leveling, per sq ft | $0.75 - $4.00+ per sq ft |
| Excavator + operator, hourly | $150 - $350+ per hour |
| Mobilization fee | $250 - $800+ flat |
| Minimum job callout | $500 - $1,500+ |
The Bottom Line
As-built grades and final grade certification are how a site proves it was built to plan, and in Oregon they often stand between you and inspection sign-off. Cojo is a CCB licensed and insured Oregon contractor, established 2009 and based in Hood River, serving statewide and the I-5 corridor. See our excavation services or request a free estimate to grade a site that certifies clean the first time.