RE2020 Thermal Study
Boulogne-Billancourt, Île-de-France

In Boulogne-Billancourt, the built density produces significant solar masking and a marked urban heat island effect, two parameters that the thermal calculation must incorporate on the basis of the real morphology rather than standard assumptions. The office stock, strongly represented, is directly affected by the tertiary sector eco-energy scheme, which steers a significant share of assignments towards renovation in occupied premises. For housing, the compactness constraint imposed by land pressure serves envelope performance but complicates the handling of summer overheating.

Summer comfort is the sticking point of the RE2020 in Boulogne-Billancourt: on exposed façades, the degree-hours (DH) threshold is quickly exceeded, all the more so in the south of France. Dynamic thermal simulation arbitrates between thermal inertia, solar shading and natural ventilation before the building envelope is fixed.