How it works
From scan to verifiable measurement
From a walkthrough with a scanner to the billable quantity: How geometry, surfaces, and billing rules can be captured in a single pass today – and what you need for it. A look at the workflow we use to relieve construction companies of quantity takeoff and supplementary documentation.
Aug 26, 2026
Scan-based measurement captures the geometry and surfaces of a building in a single walkthrough and provides a structured billing basis from it. This article describes the process step by step.
The process in four steps
Laser scan and 360° panoramas in one walkthrough – you or our partners scan the building
Automated derivation of walls, openings, and rooms, verified by a modeler
AI-assisted recognition of surfaces and equipment, attributed room by room on the model
Quantity takeoff oriented towards billing rules – not just on raw actual measurements
What you additionally get
Complete status documentation of all rooms before the start of construction, usable for supplementary claims and hidden defects
Limitations
Curved walls, concealed MEP, already covered-up works
Reading time: approx. 6 minutes
Measuring is rarely the problem.
Anyone who bills regularly knows this: the measurements themselves are taken in a few hours. It becomes time-consuming afterwards – when measurement sheets, construction plans, photos, Excel lists, and the bill of quantities have to be merged. When measurements are missing in the plans or are distributed across several planning areas. When every progress billing has to be updated with what has been added since the last time. And when, in the case of subsequent claims, you have to prove retrospectively what the inventory actually looked like before the start of construction.
This is exactly where scan-based measurement comes in. Today, the path from the inventory to the billable quantity can be largely mapped digitally. In this article, we provide an overview of the current technical possibilities and limitations. We describe what the process looks like in practice, where it ends, and what you need to contribute to it.
Step 1: On-site recording
At the beginning, there is a laser scan of the building. It captures the geometry of the rooms as a point cloud. At the same time, 360° panorama photos of each room are created. Both data sources are generated during a single walk-through of the building.
Who does this walk-through is up to you: many of our clients do the scanning themselves because they already have the equipment in-house – in that case, you deliver the registered point cloud to us, and we take over from there. Where this is not the case, our partners come with their own technology.
A note that is more important in practice than it sounds: the quality of the scan determines everything else. Poorly registered scans – for example, because standpoints were not cleanly linked – cannot be repaired afterwards. Therefore, if you scan yourself, we check the data basis before starting and report back if rework is needed.
Step 2: From point to geometry
From the point cloud, we algorithmically generate a basic model: walls, openings, levels, and room boundaries are segmented and derived as geometry, compatible with Autodesk Revit. This replaces the manual tracing of the point cloud, which makes up the largest block of time in classic methods.
Afterwards, every model undergoes quality assurance by a modeler who corrects incorrect segmentations and clarifies ambiguous cases. This is deliberate: if you later present the quantities to a client, someone must be able to stand behind them. An algorithm that gets it wrong on a crooked wall can cost you more in case of doubt than the entire process saves.
For the measurement, we deliberately work with a pragmatic level of detail. You don't need a model at the execution planning depth for billing – you need reliable areas, rooms, and component references.
Step 3: What lies on the surfaces
Geometry alone is not enough for billing. A wall area is not yet an item in the BoQ – what is crucial is what lies on it.
That is why we analyze the panorama photos with the help of AI and assign the results room-by-room to the model: materials and surfaces on walls, ceilings, and floors, as well as fixtures like radiators, lights, sprinklers, or sockets. This information is attached as attributes to the individual wall sections and rooms.
In practical terms, this means: instead of a flat wall area, you get a differentiated analysis. The tiled area in the sanitary zone is shown as a separate area portion, not as part of the overall wall. Where the plaster is missing and the masonry is exposed, this is shown in the model. Where a suspended ceiling has already been removed and concrete is visible above instead of a plaster look, this is also shown.
This is the part that experienced billers usually value the most – higher than the pure model creation. Because the assignment of "which area belongs to which item" is the actual painstaking work.
Step 4: Why the exact measurement is not yet a billable quantity
This is the point where many scan offers stop – and where the work for a biller actually begins.
The measured quantity is not the quantity to be billed. The VOB/C specifies separate billing and over-measurement rules for each trade. Openings up to certain sizes are over-measured, claddings and connections follow their own rules, and anyone who bills the actual measurement instead risks deductions in the audit. A millimeter-accurate scan therefore delivers precise geometry, but not yet an auditable position.
We therefore map these rules in the model as far as they can be derived from the geometry and the recognized surfaces – openings below the over-measurement limit are treated accordingly instead of simply being deducted. The quantities you receive from us are thus oriented towards the billing logic and not just the tape measure value.
This cannot be fully automated, and no one should promise that either. Which rule applies depends on the trade, the contract, and the specific item. What we deliver is a structured, rule-aware basis – the assignment to your BoQ items and the final evaluation remain with you or your biller. This is not a limitation we regret, but a division of labor we believe is right.
What remains as an extra: Traceable condition documentation
The panorama photos remain after the project is completed – as a seamless, spatially located record of the condition before the start of construction.
The benefit usually only becomes apparent later. When a hidden defect appears, when it is disputed whether a service was included in the original scope, or when a subsequent claim needs to be justified, the question is almost always the same: what did it look like before? A retrospectively gathered collection of mobile phone photos rarely answers this convincingly. A complete room documentation does.
This does not replace a formal evidence preservation procedure. But it regularly changes how a conversation about subsequent claims goes.
Where the process reaches its limits
Four limitations you should know before working with us:
Curved geometry. Our automated wall detection is designed for straight walls. Round or curved wall profiles – stadium buildings, curved terminal buildings, historical circular buildings – are currently modeled manually by us. For such projects, we will tell you before submitting a quote, not after.
Lines and ducts. Lines and ducts can be documented. However, automated detection of lines, pipes, etc., is not yet possible. We can document these with the point cloud and photos. If these are required in the BIM model, we model these objects manually on request.
Services already built over. Anything that is already closed up at the time of recording does not exist for the scan. This requires documentation at the right time – such as an additional recording of the drywall before it is closed. This can be planned, but not made up for later.
Daywork services. They result from an instruction, not from geometry. No scan in the world will capture them.
We state this so clearly because scan technology is regularly sold in the market with expectations that it does not meet industry-wide. Where exactly reality capturing ends and a reliable model begins, we have detailed more comprehensively in our technical article for Bauen Aktuell (Issue 4/26).
What this means in practice
The process runs at a throughput of around 2,000 m² per day – from the point cloud to the structured handover. For a medium-sized school building, this means a few days instead of several weeks during which someone from your team walks through rooms.
We are currently working, among other things, under a multi-year framework agreement with a medium-sized construction group, predominantly in the demolition and hazardous substance remediation sector for public buildings. There, the measurements serve internally as a basis for billing and measurement auditing.
How you can test this without having to take our word for it
The easiest way is a real case. If you have a point cloud from an ongoing or completed project, send us a section – we will evaluate an area and you will see on your own rooms what comes out of it and where the limits lie. No effort on your part other than the upload.
If you are not scanning yet, we will show you the workflow using an ongoing example, and you can decide afterwards whether a test project is worth it.
