Behind the Scenes: How AKN Verifies As-Built Survey Accuracy Before Delivery

When it comes to as-built surveys, accuracy isn’t just a promise — it’s a process. Before any drawing or report leaves our office, it goes through a rigorous internal verification system designed to ensure it represents the true on-site conditions — precisely, completely, and confidently.

At AKN Engineering, we take quality assurance seriously. Whether we’re working on highways, civils, or infrastructure projects across Hertfordshire, Bedfordshire, Buckinghamshire, Northamptonshire, Essex, Cambridgeshire, Norfolk and Suffolk, our internal checking process ensures that by the time your as-built survey reaches you, it’s already been through multiple layers of accuracy control.

An AKN Site engineer compares on-site measurements with design data to verify as-built accuracy on a newly completed highways scheme in Hertfordshire.

1. Control and Reference Verification

It all starts with the control network. Before processing begins, our engineers check every survey control point and benchmark to confirm they’re correctly tied to the established datum and coordinate system tied to the project control network (typically OSGB36 National Grid or a bespoke site grid).

We cross-check GNSS and total station data to confirm consistency, ensuring the foundation of your as-built model is rock solid.

For reference, UK standards for surveying and setting out highlight the importance of verified control frameworks in accuracy assurance (CITB Training Standards).

2. Raw Data Integrity Checks

Next, we review the field data in its raw state — checking for missing points, irregular shots, and station reoccupations, ensuring complete coverage and measurement redundancy for critical features. Our engineers confirm that all instruments were properly calibrated and that the logged timestamps align with on-site operations. This prevents subtle errors from creeping in during processing and guarantees data traceability for every point and feature.

3. As-Built vs. Design Comparison

Once data is processed,  where the design information is available we overlay the as-built model against the design or issued-for-construction drawing. Any discrepancies outside agreed tolerances are flagged for further investigation. This comparison process ensures that what’s built on-site matches what was intended — or, where variations exist, they’re recorded clearly and transparently.

We follow guidance from the Institution of Civil Engineers on maintaining measurement precision and survey quality (ICE knowledge Hub).

4. QA Checklist: Our Pre-Sign-Off Steps

Before anything is issued to the client, every project passes through our internal QA checklist:

✅ Control network verified and signed off

✅ Instrument calibration logs reviewed

✅ Raw data integrity checked for completeness

✅ Survey model or drawing reviewed for missing features

✅ Tolerance deviations checked and recorded

✅ As-built vs design comparison reviewed

✅ Peer review by a second engineer

✅ Final approval by a Senior Site Engineer

Each step is documented within our internal QA records to ensure full traceability — a critical part of quality management under ISO 9001 quality management systems.

5. Peer Review and Final Verification

Finally, a second engineer conducts a peer review to ensure nothing slips through. This extra layer catches human oversights and maintains our internal standard of precision. Only once the data passes peer verification do we issue the final deliverable to the client — whether that’s a DWG, PDF, or 3D model.

Why It Matters

For project managers and engineers, accurate as-built data means fewer queries, less rework, and smoother client handover. At AKN Engineering, our verification process not only safeguards your project’s accuracy but also supports compliance, record-keeping, and future maintenance documentation.

From small civils to major highways projects, we make sure your as-built survey is right — before it ever reaches your desk.

Talk to Us

If you’d like to learn more about how we manage data verification and accuracy across our surveys, contact us here, or call ☎️ 01279 927 033.