NatLabRockies/EnergyPlus

EnergyPlus is the global industry standard for building energy modeling. It is backed by the US Department of Energy (NREL/LBNL) and represents decades of validated physics-based simulation. Its defensibility stems from extreme regulatory gravity, deep integration into architectural workflows, and a massive ecosystem of derivative tools (OpenStudio, etc.). Frontier labs are unlikely to compete here as it requires domain-specific civil/mechanical engineering expertise rather than general-purpose AI.