Laser scanning questions, answered

A way of measuring surfaces in three dimensions by sweeping a laser across them. The scanner records the position of millions of points, building an exact digital copy (a point cloud) of a road, slab, room or garden that can be measured and compared with a design.

Our Trimble X9 is specified at 2 mm range accuracy and 2.3 mm 3D point accuracy at 10 m. Each finished survey also has a registration error, which shows how well the individual scans tie together, and we put that on every report.

Plot checks start from £85 per plot when four or more are scanned together, road scans from £495 a visit, measured building surveys from £325 and garden scans from £395. Every job gets a fixed price first. See the price guide for details.

Road and plot QC reports are normally with you the next working day. Measured building and garden surveys take three to five working days for drawings.

The whole of the Midlands as standard: everywhere within 50 miles of Corby is covered with travel included, from Nottingham and Coventry to Peterborough, Milton Keynes and Cambridge. We also work anywhere else in the UK, with travel charged separately.

Yes. We tie the scan to site control and compare every point with the design surface, then report the deviation and pass/fail against your adoption tolerance.

Yes, if we scan the layer underneath before the tarmac is laid. Scanning again afterwards and comparing the two surfaces gives the thickness at every point.

Slab flatness, brickwork and blockwork dimensions against the house-type drawing, and drain collar positions against the drainage layout. It doesn't check the plot's position on the site grid or level to site datum.

Yes. It captures walls, openings, out-of-square corners and services accurately enough to design from. Worktop fabricators normally still template after the units are fitted.

Yes, with every service, in E57, LAS, RCP or PTX.

Yes. The Trimble X9 uses a Class 1 laser, eye-safe under IEC EN 60825-1, so people can keep working around it.

Light drizzle is usually fine; heavy rain and standing water are not, because water affects the readings. If the weather is wrong for the check, we rebook.

Our team does, on every job. The scanner and software capture and process millions of points, then we go through every report ourselves: we check the scans tie together properly, sense-check the results against the drawings and the site, and flag the problems we find. If something looks wrong we talk it through with you before you rely on it.

Yes, on any groundworks or civils project, whether you are the designer, the client or the contractor. The Dimensure Design Audit reviews the drawings for levels, drainage, foundation and cross-drawing problems, and gives you a graded issue log with suggested fixes for your designer and indicative costs. From £495 per site.

No. We check and record what's built. Setting out stays with your site engineer, and our checks are designed to sit alongside their work.

On construction sites, someone needs to sign us in and show us the control and the work to scan. For homes, we need access to the rooms or garden; you don't need to stay for the whole visit.

They measure differently. A total station measures individual points very precisely and is the standard tool for setting out. An RTK GPS rover measures points quickly over open ground but is typically good to around 15 to 30 mm in height. A laser scanner measures millions of points across a whole surface, so it suits checking finished roads, slabs and rooms against design rather than setting them out.

Yes. We supply point clouds in E57, LAS, RCP or PTX. RCP and E57 open through Autodesk ReCap and link into AutoCAD, Civil 3D and Revit, and E57 and LAS open in CloudCompare and most survey and design packages. Drawings come as PDF and DWG. Tell us what software you use when you book and we match it.

Our standard deliverables are QC reports, 2D CAD drawings and the registered point cloud, which links straight into Revit for your team to model from. Producing a full scan-to-BIM Revit or IFC model is a separate piece of work; tell us what you need when you enquire and we will confirm whether it can be quoted.

For road and tarmac checks, yes: two or three control stations or benchmarks so the scan sits in the site's coordinates and levels and can be compared with design. Plot checks compare the plot with its own drawings, so they don't rely on site datum. Building and garden surveys use their own local grid, and gardens can be tied to Ordnance Datum on request.

Partly, and that's the adopting authority's decision. A before-and-after scan maps tarmac thickness across the whole road, and many authorities accept it alongside a reduced number of cores, placed where the scan shows they're most useful. It only works if the layer underneath was scanned before it was covered; for tarmac already laid without a 'before' scan, coring is the option.

Yes, as a measured and dated record of what was built. A Dimensure report shows exactly what was checked, the result against your tolerance and the registration error, and you keep the point cloud. It supports, but doesn't replace, inspections by the adopting authority, warranty provider or building control, and it doesn't sign anything off.

Each scanner set-up takes minutes, so time on site depends on how many set-ups the job needs. A half-day typically covers 200 to 300 m of estate road, a run of plots can be scanned in one visit, and most homes and gardens are surveyed in a single visit. Bends, small rooms, walls and dense planting add set-ups.

Problems that would cause trouble on site: levels that don't work, drainage falls, inverts and cover depths that don't add up, foundations that conflict with trees, drains or services, and drawings that disagree. A key part is checking that details and specifications are actually carried onto the layout and engineering drawings, which is where many faults hide. Each issue is graded with a suggested fix and indicative cost.

Most work is booked within a few days, and local site checks around Corby can sometimes be fitted in sooner if the scanner is free. For road work, book the sub-base scan as soon as surfacing is programmed, because it can't be done once the binder is down. Regular weekly or fortnightly visits mean plots never wait for a slot.

You don't have to use our scanner. We can do the survey and the report, or just the reporting: send us a laser scan, drone survey or your own engineer's levels with the design and tolerance, and we process it and report it against design in the same format as our own checks. There is no site visit, so it is available anywhere in the UK.