A group of craftsmen uses BIM for an energy renovation
Who said that the digital model was reserved for large construction companies?
To simplify the renovation and installation of the technical equipment of this Toulouse home, six companies have used the modeling software Recap Pro and collaborative platform Kroqi.
Who said that the digital model was reserved for large construction companies? The Alliance Rénov group, a meeting of six SMEs from the Toulouse region, proves the opposite with the use of the Recap Pro modeling tool and the Kroqi collaborative platform to facilitate exchanges between the state bodies. This old house in Toulouse consisted of three buildings, dating from three different periods and built according to distinct construction techniques. The digitization of the total living space of 270 m² considerably simplified the preparation of this complex project.
"The use of BIM has allowed us to know exactly the thickness of walls or to identify areas more suitable for the passage of ducts or water pipes", explains the plumber Pierre Mas, who ensured the realization of the model. Thanks to the sharing of 3D plans, companies have been able to coordinate better to limit network congestion and facilitate the installation of technical equipment.
On this unusual site, each of the three parts of the house included one or two water heaters located in the living rooms, as well as vintage radiators with very variable performances. The choice of an air-to-air heat pump made it possible to limit the heating and air-conditioning equipment to three outdoor units, associated with indoor units for the diffusion of air in each room. Two water heaters positioned in non-habitable spaces will ensure the production of hot water for the entire house, with a relay balloon to limit losses in the water rooms on the ground floor. Begun in May, the site is scheduled for completion this fall.
Working in a global renovation
The building
Image source: Le Moniteur
Three building blocks, three eras, three solutions. The first part, built in the 1900s, with thick brick walls and a correct thermal inertia, only required attic insulation with 200 mm of glass wool. On the extension made in the 60s (photo), the most problematic, all the walls were insulated from the inside and new double-glazed windows and French windows were installed. On the extension dating from the 80s, only the doubling of the walls from the inside has been achieved.
The scanner
This is the originality of the project: the realization of a 3D plan of the house thanks to a scanner connected to the software Recap Pro. The operation is done in each room: the tool is then responsible for linking "point clouds" to generate the digital model. The precision of the ribs is millimeter.
The software and the platform
Image source: Le Moniteur
Here is a view generated from the Recap Pro software. The files have been uploaded on the Kroqi collaborative platform, accessible to Alliance Rénov companies. Everyone can download the model and modify it, check a measurement, propose a modification of the works or check the progress of the other lots.
In the Attic
Image source: Le Moniteur
The 3D model makes it possible to better position the equipment according to the frame. Here, the group has proposed to the customer to place a water heater in the attic to gain living space: the device will be positioned very precisely above a wall of splits to better distribute the weight, and on a tray of zinc retention to prevent seepage in case of leakage.
CAP
Image source: Le Moniteur
Stéphane Evrard (Clim & Chauff company) installed a Hitachi air/air heat pump that combines summer comfort and energy savings. Three groups were positioned on the roof to recover the external calories in winter, and evacuate the indoor heat in summer. DC Inverter technology ensures a more constant temperature and up to 40% lower consumption than conventional reversible air conditioning systems.
On the roof
Image source: Le Moniteur
If interventions on the envelope were limited, a major intervention was needed: the removal of the roof of the extension of the 60s, too damaged. The opportunity to pass the networks of reversible air conditioning, before the installation of the new cover. For the part built in the 80s, it was necessary to pass the networks through the roof terrace.
