ONLINE BRUSSELS HERITAGE - ONE-DAY SEMINAR - 11/12/2014

For the façades an extensive range of solutions was examined. Firstly, the possibility of keeping the existing façade was explored, but this was very difficult to justify in terms of energy performance. Installing a new skin in front of the old skin could not be justified in terms of heritage, particularly as the building is built on stilts.

Another idea was a metal structure with integrated windows as a new type of prefab system, finished with insulation and a type of plaster. This solution deviated too greatly from the project and gave nearly no thermal inertia to the building. Finally, the architects went back to the idea of using concrete prefab elements again, but this time with a new prefab element that completely covered the structure, thus avoiding cold bridge problems - either at floor level or around the columns - and with the following element: 12 cm concrete on the interior, 15 cm polyurethane insulation and then 7 cm concrete on the exterior.

Regarding the design for the façade, Willy Van Der Meeren's concept was used again, including the same design parameters. Two additional parameters were added in order to determine the design: on the one hand fire safety and on the other energy performance (fig. 13 and 14). In this concept, the outermost arch was first dismantled and a new beam installed on which the new façade could be hung. In order to solve the fire safety problem of the new façade, a type of nosing was integrated into the façade. The developing length measured at one metre. This solves the fire spread problems and means that it is still possible to integrate a fair number of windows.

Fig . 12a, 12b and 12c

12a: original building by Willy Van Der Meeren (© Willy van der Meeren Archives). 12b: the building before renovation; showing the brick stair shafts covered due to water infiltration. They were equipped with a metal cover long ago (© G. De Kinder). 12c: a drawing of the final project (© Origin).

80 | Ieder Zijn Huis: the renovation of a modernist social housing tower block