Scan to BIM: from point cloud to BIM model

Every intervention on an existing asset starts with a simple question: how is it really built? The answer does not lie in archive drawings, which are often incomplete or out of date, but in the survey. The BIM model of the existing conditions turns millions of points into information that designers, contractors and asset managers can use.

What scan to BIM is: from point cloud to BIM model

A laser scan survey produces a point cloud: a very accurate geometric snapshot, but one with no constructive meaning. It cannot tell a column from a wall, or a building service from a structure. This is what the scan to BIM process is for: interpreting the cloud and rebuilding the elements as parametric objects, classified and carrying information.

We start from the point cloud provided by the client's surveyor: this is where our work of interpretation and checking makes the difference.

What makes an existing conditions BIM model reliable?

A good model of an existing asset is not the most detailed one, but the one fit for purpose. That is why, before modelling, we define together with the client:

• the level of information need (LOIN, UNI EN 17412-1), based on what the model will have to support: restoration design, upgrading, maintenance;
• the acceptable tolerances against the point cloud, to be declared and documented;
• the rules for classifying and naming the elements, in line with UNI 11337 and ISO 19650;
• the final check of the model against the original survey.

Why the existing conditions model matters for the whole life cycle

A well-built model of the existing conditions reduces surprises at the design and construction stages, because clashes with what already exists emerge earlier. In historic buildings, where irregularities and stratification are the norm, this phase is even more decisive.

And it does not end at the initial stage: it is the basis on which the same model grows, being coordinated during design, guiding construction and, at handover, becoming the as-built model for operating the asset.

That is why, at B1P Group, “the asset comes before the asset”: before the intervention is designed, we get to know the asset that is already there. Every project starts from a model built with method, because everything that follows inherits its quality.

Scan to BIM: frequently asked questions

What is scan to BIM?

It is the process that interprets the point cloud of a laser scan survey and rebuilds the existing asset as a BIM model, with parametric elements that are classified and carry information.

Is a point cloud already a BIM model?

No. A point cloud is a very accurate geometric snapshot, but it cannot tell a column from a wall: it becomes a BIM model when the elements are rebuilt as objects and classified.

How detailed should the existing conditions model be?

As detailed as its purpose requires. The level of information need (LOIN, UNI EN 17412-1) is defined according to what the model will have to support: restoration design, upgrading or maintenance.

Who carries out the laser scan survey?

The client's surveyor. B1P Group starts from the point cloud provided, interprets it and derives the BIM model of the existing conditions, checking it against the original survey.

Do you want to understand how to set up the model of the existing asset for your project? Let's talk about your project.