GPR SURVEYS

A GPR Survey (Ground Penetrating Radar Survey) uses radar pulses to detect and map underground utilities, voids, and structures.
It’s a non-intrusive method that can identify non-metallic services (like plastic water pipes or concrete ducts) that electromagnetic (EML) methods can’t detect.
It’s often used as part of a PAS 128 Type B Utility Survey to confirm the presence and depth of buried services.

Although GPR is powerful, it has limitations:

• Highly conductive or saturated clay soils reduce radar penetration

• Metallic reinforcement in concrete can obscure deeper reflections

• Deep utilities (typically >3m) may not be visible in all conditions

Our engineers assess soil type, ground conditions, and site layout before scanning to set realistic expectations.

If visibility is limited, we recommend combining GPR with Electromagnetic Location (EML) — see our Underground Utilities Surveys page for details.

Yes — if your site includes non-metallic services, complex ground conditions, or uncertain utility records, a GPR survey helps reduce the risk of utility strikes.
It’s a key component of PAS 128-compliant utility mapping, which supports compliance with HSG47 (“Avoiding Danger from Underground Services”) and CDM Regulations 2015 (HSE.gov.uk).

If you’re still at the design or planning stage, start with a Utilities Desktop Search to gather statutory records before commissioning on-site surveys.

Accuracy depends on several factors:

• Soil composition and moisture

• Antenna frequency (typically 250 MHz – 800 MHz)

• Ground surface conditions and survey grid density

Under PAS 128:2022, GPR surveys typically achieve Quality Levels QL-B1 to QL-B4, with depth estimates usually within ±10% of actual depth in favourable conditions.

Yes. GPR can penetrate reinforced concrete, asphalt, and paved surfaces, making it ideal for highways, car parks, and urban sites. It's commonly used for void detection and service location beneath hardstanding areas.

We use multi-frequency radar systems such as the Leica DS2000, IDS Stream, and MALÅ GPR units — depending on site conditions and project scope.
These deliver high-resolution data that can be processed into depth slices, cross-sections, and 3D radar volumes for clear visualisation.

All AKN Engineering GPR Surveys are completed in accordance with:

• PAS 128:2022 — Specification for Underground Utility Detection

• HSG47 — Avoiding Danger from Underground Services (HSE.gov.uk)

• CDM Regulations 2015 — Safe excavation and design practices

We also follow manufacturer calibration guidance and site-specific method statements.

You’ll receive:

• CAD drawings (DWG, DXF, PDF) with annotated utilities and anomaly positions

• Depth and confidence data

• Interpretation report with findings and limitations

• Supporting radar cross-sections and site photos (if required)

Outputs can be integrated directly with your Topographical Survey or Utility Record Plans.

Our GPR teams can usually mobilise within 3–5 working days, depending on project location and access requirements.
If you already have a desktop search or site plan, we can quote and schedule even faster.

Pricing depends on:

• Site area and access conditions

• Complexity of the underground environment

• Whether combined with EML detection or topographical surveying

We offer transparent, fixed-cost quotes for each project. Contact us on 01279 927 033 or request a quote online for a tailored estimate.

Yes — GPR is most effective when used alongside:

• Electromagnetic Location (EML) for metallic utilities

• Topographical Surveys for accurate surface context

• Utilities Desktop Searches for statutory record verification

We offer complete utility mapping packages, combining all three for end-to-end PAS 128 compliance.

Yes. Our post-processing workflow can generate 3D radar volumes and subsurface models, ideal for complex sites and BIM integration.
These outputs can be exported in standard formats for use in AutoCAD Civil 3D or Revit environments.