3D laser survey and BIM model of 9 apartment blocks

A complex of four blocks of flats

The project concerns an exclusively residential complex made up of nine buildings organised into four separate bars. The layout of the plot follows the natural topography of the land, resulting in height discrepancies between each building and making it difficult to read the overall elevation.

The total surface area is 15,000 m², divided between 10,000 m² of living space and 5,000 m² of basements. The communal garages occupy a significant area and are a central feature of the site's organisation.

3D scan of a residential building in Crans-Montana - point cloud for a local architect using Archicad

Complete digitisation of a residential complex of 9 buildings in Fribourg representing 15,000 m². A single one-week campaign with three teams, structuring in a master file integrating the topography and communal garages, individual modelling per building bar and management of multiple altimetries.

A complex of four blocks of flats

The project concerns an exclusively residential complex made up of nine buildings organised into four separate bars. The layout of the plot follows the natural topography of the land, resulting in height discrepancies between each building and making it difficult to read the overall elevation.

The total surface area is 15,000 m², divided between 10,000 m² of living space and 5,000 m² of basements. The communal garages occupy a significant area and are a central feature of the site's organisation.


A methodology identical to that used for our major projects

As with our large-scale operations, the project was structured around a central master file. This file contains the complete topography, the shared garages and the cross-functional elements required to ensure the overall consistency of the model.

Each building bar was treated separately. Modelling was carried out building by building in order to guarantee the performance of the files, the accuracy of the controls and the legibility of the levels. Once validated, the models were integrated into the master file, ensuring complete coordination across the site.

This organisation enables independent work to be carried out on a building without compromising the coherence of the whole.


Precise height management

The main technical difficulty lay in managing the levels. No two buildings are at the same entrance altitude. The accesses, basements and external walkways are constantly offset by the natural slope of the land.

The project was not georeferenced. A zero point has been defined at the entrance to the lowest building to serve as a common height reference. This choice guarantees the internal stability of the model and enables it to be adapted to a geo-referenced system at a later date, if necessary.


Organisation of the survey on an occupied site

The scanning was carried out in a single week-long campaign with three simultaneous teams. The work was planned precisely in order to limit any inconvenience to occupants.

Each dwelling was integrated into a schedule based on two-hour time slots, enabling teams to rotate smoothly and progress continuously across the four building blocks. This organisation made it possible to avoid multiple returns and to secure the survey campaign throughout the perimeter.

3D scan of a residential building in Crans-Montana - point cloud for a local architect using Archicad

From survey to delivery

The time between the start of the survey and the final delivery of the plans and the BIM model was two months. This period enabled the point clouds to be assembled and checked, the project to be structured in terms of altimetry, the buildings to be modelled progressively and integrated into the master file.

Each stage was systematically checked to ensure consistency between the topography, basements and residential volumes.


An operation representative of our approach

This project illustrates our ability to work on large residential developments, to structure complex models on the scale of an entire site and to manage multiple altimetries in a demanding topographical context. It also demonstrates our organisation on an occupied site and our ability to maintain a tight deadline despite the scale of the survey.

Master file structuring, combined with independent processing for each building, is now a standard method for all our projects exceeding several thousand square metres.