Sheet 01 · Survey plan
PAS128 · GPR · Drainage
PAS128 utility mapping, GPR, drainage and confined-space surveys — from a desktop record search through to vacuum excavation, so the drawing you design from is one you can build from.
Colour is the record. Four utilities, four colours, for the whole page.
01 — Before you dig
Records go out of date. Services get moved, added, abandoned and never redrawn; drawings arrive in the wrong coordinate system, or with the last twenty years missing. PAS128 exists because of that gap — it sets out how a service is found on site, and how much confidence the drawing that comes out of it actually carries.
a
The record is a starting point. A desk study tells you what should be there. It cannot tell you where it is, or how deep.
b
Detection is a measurement. GPR and electromagnetic location place the service on a coordinate, tied in by GPS or total station.
c
Verification is proof. Where the level demands it, vacuum excavation exposes the service and its position stops being an inference.
02 — Schedule of services
From a basic lift-and-dip of the manholes through to a high-specification PAS128 survey — the whole chain is in-house, including the excavation that verifies it.
| Ref | Service | Method | What it finds |
|---|---|---|---|
| 01 | PAS128 Utility Mapping | PAS128, types A–D | Where each service runs, at the level of confidence you ask for. |
| 02 | Desktop Utility Record Searches | Statutory records · type D | What the drawings say is there, compiled onto one base. |
| 03 | GPR Surveys & Post Processing | Ground penetrating radar | Non-metallic services, voids and obstructions the records miss. |
| 04 | Drainage Connectivity | Manhole lifting, dipping, tracing | Which chamber connects to which, and in which direction. |
| 05 | Borehole Clearance | Clearance reports, percussion and auger | A cleared position for each borehole before the rig arrives. |
| 06 | CCTV Drainage Surveys | CCTV condition survey | Pipe condition, defects and connections inside the drain. |
| 07 | Confined Space Entry | Certified confined-space surveyors | Chambers and culverts a general survey team cannot enter. |
| 08 | Concrete Scanning / Ferro & Rebar Detection | Cover meter and scan | Rebar, post-tension and conduits before you drill or core. |
| 09 | High Pressure Water Jetting | High pressure jetting | A clear pipe to survey, and a drain that flows again. |
| 10 | Vacuum Excavation | Vacuum excavation, trial holes | The service itself, exposed — the proof behind type A. |
| 11 | Land & Measured Building Surveys | GPS and total station | A base map at survey accuracy to draw the services onto. |
| 12 | Site Engineering Surveys / Setting Out | Setting out from the design | The design, marked on the ground where it will be built. |
What comes back
Two of the things the work produces. A plan sheet to design from, and a clearance sketch to hand to a drilling rig.
03 — PAS128 quality levels
PAS128 sets out four categories of survey, each weighing more time and effort against more confidence in the result. You choose the level. We will tell you when a lower one would do — and when it will not.
A
Detection, then proof. Trial holes or trenches — often opened by vacuum excavation — expose the service so its position, depth and identity are confirmed on site. The highest confidence the standard describes.
detected + exposed
B
Detection without excavation. GPR and electromagnetic location trace the service and it is surveyed in. The position is measured; depth and identity rest on the response, not on an open trench.
detected, not exposed
C
Records, tested against the site. Chambers are lifted and dipped, covers and markers are walked, and the drawing is corrected wherever the site disagrees with the paper.
records + walkover
D
Records only — statutory authority drawings and any archived survey, compiled onto one base. No site work at all, so it shows what is recorded rather than what is there.
records only
Not to scale. The four categories are ordinal: the standard sets them out, and the depth of work in each is agreed with you before the survey starts. Every level is delivered in-house, up to vacuum excavation of trial pits and trenches.
Specifying a survey?
The PAS128 discussion document walks through the options, so you can pick a level rather than guess at one.
04 — Case studies
A survey only proves something if it was done on a real site, against a real constraint. These are the ones the team has published.
| 01 | PAS128 Type A Survey |
|---|---|
| 02 | Underground Utility Survey |
| 03 | LV Electric Feeder Location |
| 04 | Steel Frame Location |
| 05 | Concrete / Ferroscan Survey |
| 06 | CCTV Report |
05 — Access and safety
Drainage connectivity, CCTV and jetting all need someone at the bottom of a manhole. Confined-space entry is its own competence — certified surveyors who can work inside a chamber, culvert or deep manhole instead of photographing it from the top.
06 — Where we are
Regionally based staff, so the crew that surveys your site is the one that can come back to it — and the one that knows the local authority records.
Birmingham HQ
Unit 2 Regal Court, Kings Norton Business Centre,
Kings Norton, Birmingham B30 3FJ
Thames Valley Reading
Unit 311, Bizspace Theale, Merlin House,
Theale, Berkshire RG7 4AB
London
G.3 Bedford House,
69–79 Fulham High Street, London SW6 3JW
Bristol
2 Redcliffe Way,
Bristol BS1 6NL
Ipswich
The Hub Business Centre, Hubbard Way,
2 Civic Drive, Ipswich IP1 2QA
07 — Get in touch
A record drawing, an old survey, or nothing at all. Tell us what you are building and when the ground opens, and we will tell you what has to be found before then.