
More than a technology, it is a working method based on the sharing of reliable information throughout the lifespan of a building or infrastructure, around a digital 3D model.
Among its many advantages, BIM should also make it possible to improve the carbon footprint of buildings and promote energy renovation. Update on these issues with Matthieu FERRUA, director of the BIM Factory at ENGIE Solutions.
Can you recall what BIM actually consists of?

BIM is a 3D model technology that integrates data across the entire building lifecycle, from design to deconstruction, including construction, operation and maintenance.
Conceptualized since the 70s / 80s, BIM took off in the 2000s in the field of industrial construction and through some innovative architects like Frank Gehry, to facilitate the creation of complex architectural forms. This type of modeling already existed in the aeronautics and automotive industry, but was only used late in the building sector, where it has gradually gained ground since the mid-2010s.
The main advantage of BIM is that it makes it possible to coordinate the data of different trades involved in the same building, whether it is architecture, plumbing, climate engineering, electricity ... .
This is the whole challenge of "BIM Management" to ensure that these data, geometric and information, are consistent, well ordered and shared as early as possible. This pooling makes it possible to anticipate, to better visualize and to appropriate the works.
For the building sector, BIM is the gateway to the era of digitization. It is a question of catching up a certain delay because, in comparison with other industrial sectors, the building world has changed little since the 1950s. BIM is indeed an immense asset for improving speed, quality and modularity of constructions. It is also a key component of the digital twins of tomorrow. We are only beginning to see the benefits.
How can BIM improve the carbon footprint of a building?
BIM is a great tool for calculating the carbon footprint of a project.
Concretely, BIM technology makes it possible to model “BIM objects”, such as an outlet, a valve or a section of wall, by integrating information, in particular the quantity of associated carbon.
At ENGIE Solutions, we have started using this technique, through the ValoBIM © offer, to optimize the potential for reuse of existing building components and enrich circular economy ecosystems.
Upstream of the deconstruction phase, a resource diagnosis is carried out and integrated into a BIM model, which allows us to produce an exhaustive report including a measurement of the carbon footprint of each object / resource, in order to optimize them: reuse, recycling, or energy recovery by incineration. This qualification of the components, located and quantified, allows us to develop reuse scenarios and optimize the total carbon footprint of the project. For example, on the ENGIE Campus project, savings of 41 tonnes of CO2, i.e. 304 round trips between Paris and New York, were identified over part of the deconstruction phase, and more than 7 tonnes of potential savings on the future project, ie 372 Paris-London return trips by plane.
We also use this technology during the design phase of structures, to determine the carbon savings linked to the choice of components (low-carbon concrete rather than conventional concrete, for example), both quickly and precisely. To put it another way, BIM helps us identify potential carbon savings sources and therefore make the most relevant choices from an economic and environmental point of view.
All of this is still very recent. We are currently working with SERCE [1] on the integration of this carbon data into the entire BIM chain. Should we calculate the carbon of the component as sold by the supplier? after transport? What about its implementation, its life cycle and its recycling potential? These are all questions that deserve harmonized answers between the various players in the building industry.
What about energy renovation?
This is another advantage of the BIM model for the energy transition of buildings. It enables the thermal balance of an existing or planned building to be produced very precisely, from dynamic thermal calculations fed by the model. By integrating them into the 3D model, we can easily identify the most relevant works to improve the performance of a building. This involves, for example, identifying a zone of thermal failure or else a room where the insulation is poorly distributed.
This energy optimization method is still in the research and development phase. We have so far tested it on ENGIE Solutions office buildings and the results are promising. The development of this technology on a large scale will have to take into account the constraints and specificities specific to each building and the new thermal regulations. BIM opens up great prospects for the future of energy renovation!