L'hypercubeIBPSA France 2026 & SIMUREX: a packed week in Lyon 🏙️
In late May, L’hypercube headed to Lyon for a week fully dedicated to urban thermal simulation. On the agenda: the IBPSA France 2026 conference, followed by the SIMUREX summer school, where L’hypercube led a hands-on workshop on view factor computation.
IBPSA France 2026
The IBPSA France 2026 conference was held in Lyon from May 18 to 22, centred on the theme of overheating in buildings. It also covered low-tech approaches, bio-sourced materials, indoor environment quality, building renovation, and all aspects of building and system modelling and metrology.
L’hypercube presented two contributions:
- a thermo-hydrological model for simulating urban ground surface temperatures,
- a quantitative methodology for designing bio-analogous climate shelters, as part of the AbriCoCoDA project.
Both papers are detailed on the publications page .
SIMUREX: the urban simulation summer school
After the conference, we stayed in Lyon for SIMUREX, a summer school dedicated to urban simulation, combining lectures and practical workshops.
The view factor workshop — powered by pyViewFactor
L’hypercube led a hands-on workshop on view factor computation, a topic central to radiation simulation methods in urban environments.
The workshop was a chance to showcase pyViewFactor , a Python library developed and maintained by L’hypercube, dedicated to computing radiation view factors between polygonal surfaces. Originally born from internship work in 2021, it is now available on PyPi and GitLab :
The library just reached an important milestone with the release of version 1.1.0 , which introduces a semi-analytical integration kernel (SA-30) and a BVH (Bounding Volume Hierarchy) acceleration structure for obstruction tests — all JIT-compiled with Numba for a measured ×33 speedup on an urban reference case. The timing with SIMUREX was perfect to share these advances with a new audience!
View factors are a fundamental parameter for estimating the mean radiant temperature (MRT) outdoors, and therefore thermal comfort: they quantify the fraction of radiation exchanged between two surfaces, whether a façade, the ground, a tree, or a pedestrian in the street.
The workshop was built around an interactive notebook, taking participants from a single pair of faces all the way to a full urban scene analysis.
All materials are available online:
- 🌐 Workshop site: matbog.github.io/simurex2026-pvf
- 💻 GitHub repository: github.com/matbog/simurex2026-pvf
- 📖 pyViewFactor documentation: arep-dev.gitlab.io/pyViewFactor
