A Complete Guide to Utility and GPR PAS 128 Surveying in the UK.
Introduction
At Cadmap Limited, we understand the importance of accurate and reliable data in construction and infrastructure projects. Utility and Ground Penetrating Radar (GPR) surveying are essential techniques used to ensure the safety, efficiency, and success of these projects. Whether you're dealing with urban developments, roadworks, or major infrastructure projects, knowing the location of underground utilities and understanding the subsoil conditions is crucial.
In this comprehensive guide, we will walk you through the basics of Utility and GPR surveying, how these services work, and why they’re essential for any project that involves subsurface construction or excavation.
What is Utility Surveying?
Utility surveying involves identifying, mapping, and recording the location and condition of underground utility networks. These networks may include water pipes, gas lines, electrical cables, telecommunication lines, and sewage systems. Utility surveys are conducted to avoid costly mistakes, prevent accidents, and optimize the planning of construction work.
Why Utility Surveying is Crucial
Safety First: The risks of hitting an underground utility during excavation are significant. Damaging gas or electrical lines can cause fires, explosions, or electrical hazards. Utility surveying helps to avoid these dangers.
Cost Savings: Mistakenly damaging utilities can lead to expensive repairs, delays, and even fines. By identifying utility lines in advance, contractors can plan their work more effectively and avoid unnecessary costs.
Regulatory Compliance: Certain construction activities require thorough documentation of utility locations. By conducting a utility survey, you ensure compliance with local regulations and avoid legal issues down the line.
Improved Project Planning: Knowing where utilities are buried underground helps project planners optimize space, reduce conflicts, and improve coordination between different construction teams.
Utility Surveying Techniques
Utility surveying uses several techniques to gather information, including:
- Electromagnetic Locators (EML): These devices send electromagnetic signals through the ground to detect utilities made of conductive materials, like metal pipes and cables.
- Ground Penetrating Radar (GPR): A non-invasive method that uses radar pulses to image the subsurface and locate utilities, including non-metallic ones like plastic pipes.
- Vacuum Excavation: A process that involves using high-pressure air or water to safely expose underground utilities for direct visual inspection.
What is Ground Penetrating Radar (GPR) Surveying?
Ground Penetrating Radar (GPR) surveying is a non-invasive, geophysical method that uses high-frequency radar waves to scan and map the subsurface. GPR can detect a wide range of underground features, including utilities, voids, rocks, soil layers, and other anomalies that could affect construction.
How GPR Works
GPR uses a transmitter to emit radar pulses into the ground. These pulses bounce back when they hit an object or a change in material, creating a signal that can be analyzed to generate a visual representation of the subsurface. The GPR system is typically mounted on a cart, which is pushed across the ground or placed on a vehicle for larger-scale surveys.
Benefits of GPR in Surveying
Non-Destructive Testing: GPR is a non-invasive method that doesn’t require digging or disturbing the ground. It provides a safe and efficient way to survey the subsurface without causing damage.
Accuracy and Detail: GPR can detect a wide range of materials, including metals, plastics, concrete, and even some non-metallic materials. The data collected provides a detailed and accurate view of subsurface conditions, crucial for construction planning.
Time and Cost Efficiency: Since GPR does not require excavation, it saves time and reduces the overall cost of a project. The data obtained is available in real-time, allowing for immediate analysis and decision-making.
Versatility: GPR is ideal for a variety of environments, from urban areas to remote locations. It can be used in almost any soil condition and is particularly effective in detecting utilities and structures buried deep underground.
Common Applications of GPR
- Utility Mapping: Detecting the location of utilities like pipes, cables, and conduits to prevent accidental damage during excavation.
- Infrastructure Assessment: Assessing the condition of roadways, bridges, and other infrastructure to detect voids, cracks, and other potential problems.
- Geotechnical Surveying: Identifying soil composition, bedrock, and other subsoil features that are important for construction planning.
- Environmental Studies: Assessing contamination and monitoring groundwater movement.
Utility and GPR Surveying at Cadmap Limited
At Cadmap Limited, we offer professional utility and GPR surveying services tailored to meet the specific needs of your project. Our team of experts uses state-of-the-art equipment and proven methodologies to provide accurate, reliable, and timely results. Whether you're working on an urban construction site, a road expansion, or an underground infrastructure upgrade, our surveys will ensure your project stays on track.
Why Choose Cadmap Limited?
Experienced Professionals: Our team of surveyors has years of experience in utility and GPR surveying. We understand the complexities of subsurface conditions and know how to navigate the challenges of various environments.
Advanced Technology: We use the latest GPR and utility detection equipment to ensure high-accuracy results. Our technology helps provide clear, actionable data, making it easier for your team to plan and execute construction tasks.
Safety and Compliance: We prioritize safety on every project. Our surveys help reduce the risk of utility strikes and ensure that your project adheres to all relevant regulations and guidelines.
Tailored Solutions: Every project is unique, and so are the surveying needs. We customize our services to suit your specific project requirements, whether it's a small-scale development or a large infrastructure project.
Quick Turnaround: We understand that time is of the essence in construction. Our surveys are completed efficiently without compromising on quality, ensuring that you get the results you need when you need them.
Conclusion
Utility and GPR surveying are essential tools in modern construction and infrastructure projects. By working with Cadmap Limited, you gain access to reliable, accurate, and comprehensive surveys that provide peace of mind and help prevent costly delays and safety hazards.
Don’t let unknown underground obstacles derail your project—contact Cadmap Limited today to discuss how our utility and GPR surveying services can support your next venture. With our cutting-edge technology and expert team, we’re here to help you navigate the complexities of subsurface surveying with ease.
For more information, reach out to us at Cadmap Limited and let us assist you in ensuring the success of your next project!
PAS128 Survey - PAS 128 Levels.
The PAS 128 standard outlines the classification of survey accuracy for Ground Penetrating Radar (GPR) surveys. There are four main levels of PAS 128 GPR, each representing a different degree of survey accuracy and detail:
Level A:
- Accuracy: High (Precise location and depth)
- Description: Fully detailed, surveyed with high accuracy, typically by GPR and supplemented with other methods if needed. All utilities and features are accurately located and identified.
Level B:
- Accuracy: Moderate (Identified with reasonable accuracy)
- Description: Utilities are located and identified with good confidence, but not to the level of precision of Level A. Depth may be estimated.
Level C:
- Accuracy: Basic (Identified, but less certain)
- Description: Utilities are identified with less certainty and often require further investigation. Data may be limited, and some features might not be as accurately located.
Level D:
- Accuracy: Low (Utility location inferred)
- Description: Survey results are largely inferred based on visual inspection, utility plans, and other indirect methods, rather than direct detection. This level is typically for less critical projects.
Each level provides a different balance of data quality and cost, depending on the project's needs.
Precision Setting Out with Total Stations and Robotic SitePRINT Technology
At CADMAP, we’ve built our reputation on delivering surveys and setting out with pinpoint accuracy. Whether working on large commercial developments, complex refurbishments, or infrastructure projects, our team combines traditional expertise with cutting-edge technology to ensure every line, level, and point is exactly where it should be.
One of the biggest advancements in construction setting out in recent years is the use of robotic layout machines such as the SitePRINT, combined with high-accuracy total stations. CADMAP has been deploying this powerful combination across multiple sites with outstanding success — saving our clients time, reducing errors, and delivering results that exceed expectations.
Why Accuracy Matters in Setting Out
Setting out is the foundation of every construction project. If it’s wrong, everything built on top of it will be compromised. Traditional setting out methods with tapes and string lines are prone to human error, and even standard total station workflows can be labour-intensive. That’s why more contractors are turning to robotic solutions supported by survey-grade control.
Total Stations: The Backbone of Precision
Our Leica total stations are the backbone of our setting out services. They allow our surveyors to:
Establish highly accurate control networks.
Transfer design data from CAD and BIM models directly onto site.
Provide rapid, repeatable, and reliable positioning.
This ensures that every subsequent stage — from structural steel to concrete pours — is aligned with millimetre accuracy.
SitePRINT Robotic Machine: Revolutionising Layout
Where the total station ensures precision, the SitePRINT robotic machine brings automation and efficiency. Imagine a robot that can mark out hundreds of points, lines, and arcs directly onto concrete or sub-base in a fraction of the time it would take a manual crew.
Key benefits we’ve seen on live sites:
Speed: Layout tasks completed up to 10x faster.
Consistency: Perfectly straight, accurate markings every time.
Safety: Reduced manpower needed on site, minimising exposure to hazards.
Integration: Works seamlessly with CAD and BIM design files.
Proven Success on Multiple Projects
CADMAP has successfully delivered projects across London, Surrey, Sussex, and the Home Counties using the total station + SitePRINT workflow. From residential developments to commercial buildings and large-scale refurbishments, the results have been the same: precise, efficient, and dependable setting out.
On one recent site, what would normally have taken a full team three days to mark out was completed in a single day with SitePRINT, underpinned by CADMAP’s control network and survey expertise.
Why Choose CADMAP for Setting Out?
When you hire CADMAP, you’re not just hiring a machine — you’re hiring a team of chartered surveyors who know how to integrate the latest technology with traditional best practice.
Fully insured with £10m Professional Indemnity.
Accredited in health and safety standards.
Experienced across construction, engineering, and infrastructure.
Equipped with the very latest Leica survey technology.
The Future of Construction Layout
The construction industry is moving towards automation and digital integration. By combining total stations with SitePRINT robotics, CADMAP ensures you’re not just keeping up — you’re staying ahead. Our clients benefit from reduced programme times, improved accuracy, and lower costs.
If you’re planning a project and want your setting out done right the first time, contact CADMAP today to discuss how our team can support your build.
📞 Call us on 01483 429385
📧 Email us at info@cadmap.co.uk
🌐 Visit www.cadmap.co.uk
Beneath the Surface: How Cadmap Limited Supports HMP Sites with PAS 128 Type B Utility Surveys
At Cadmap Limited, we’ve always prided ourselves on delivering precise, safe, and reliable survey solutions. Recently, our team of experienced topographical and utility surveyors has been working extensively across Her Majesty’s Prison (HMP) sites throughout the UK — particularly in Kent — supporting essential infrastructure upgrades with industry-leading PAS 128 Type B utility surveys.
But what does that actually involve, and why is it so important?
Surveying High-Security Sites: Not Your Average Day at the Office
Surveying within high-security environments like HMP sites presents a unique set of challenges. These are not typical construction zones. Strict access protocols, heightened security clearances, and the need for absolute precision all mean there’s zero margin for error.
Our mission? To ensure that excavation works for new fibre-optic (FAG) pipes and high-voltage (HV) electrical cables can be carried out safely, accurately, and with minimal disruption. And that’s where PAS 128 Type B surveys come in.
What Is a PAS 128 Type B Survey?
PAS 128 is the British standard specification for underground utility detection, verification, and location. A Type B survey specifically involves detection using geophysical methods — most commonly Ground Penetrating Radar (GPR) and Electromagnetic Location (EML).
This method allows our surveyors to locate buried services without excavation, producing detailed and reliable maps of underground infrastructure.
Why PAS 128 Surveys Matter — Especially Here
When working around critical infrastructure — particularly prisons, government facilities, and secure institutions — the risk of striking unknown or undocumented utilities isn’t just costly. It’s potentially dangerous.
Here’s why PAS 128 surveys make a difference:
✅ Safety First: By accurately locating buried utilities, we help reduce the risk of utility strikes during excavation — protecting workers and maintaining operational security.
✅ Time and Cost Savings: Knowing exactly where services lie reduces delays and avoids costly rerouting or repairs.
✅ Confidence in Compliance: PAS 128 surveys provide documentation and assurance that projects meet the latest UK industry standards.
✅ Non-Invasive Investigation: Perfect for sensitive sites, our surveys require no digging — meaning minimal disturbance and faster clearance to proceed.
The Cadmap Difference
At Cadmap Limited, we’re more than just surveyors — we’re specialists. All of our utility surveyors are trained to the highest industry standards, and we’re proud to be members of both the Survey Association (TSA) and the Chartered Institution of Civil Engineering Surveyors (CICES).
Our team's collective expertise in topographical and utility surveying means we can provide an integrated solution — delivering surface and subsurface mapping in one seamless service.
With decades of experience and an expanding footprint across the UK, our work on HMP sites in Kent and beyond reflects the trust placed in our ability to deliver under pressure — and with absolute precision.
Need a PAS 128 Survey You Can Trust?
Whether you’re working on a prison refurbishment, infrastructure installation, or major civil works project, Cadmap Limited is here to help. Our qualified surveyors will ensure that what's underground doesn’t stay a mystery.
📍 Based in the South East, serving the whole UK
📞 Get in touch with us today to discuss your project — and let us help you see beneath the surface.
