Building-envelope physics for a BIM energy model: paste a wall/roof/floor LAYER STACK and get the assembly U-value and R-value (ISO 6946 series resistance), the design heat loss Q = U.A.dT, the steady through-wall temperature profile, the ISO 13786 DYNAMIC thermal-mass characteristics (periodic thermal transmittance, decrement factor, time lag, areal heat capacity - what a static U-value cannot express, computed by a chain of complex per-layer heat-transfer matrices at the diurnal frequency), and a heating-degree-day seasonal energy estimate.
Building-envelope physics for a BIM energy model: paste a wall/roof/floor LAYER STACK and get the assembly U-value and R-value (ISO 6946 series resistance), the design heat loss Q = U.A.dT, the steady through-wall temperature profile, the ISO 13786 DYNAMIC thermal-mass characteristics (periodic thermal transmittance, decrement factor, time lag, areal heat capacity - what a static U-value cannot express, computed by a chain of complex per-layer heat-transfer matrices at the diurnal frequency), and a heating-degree-day seasonal energy estimate. Honest scope: 1D conduction, steady + a single diurnal harmonic; no 2D thermal bridges, moisture, or solar gain; degree-day energy is a seasonal estimate, not an 8760-hour simulation. A design-aid companion to EnergyPlus / IES-VE, not a replacement. The dynamic result is self-checked against the closed-form thermal wave Y = lambda.k/sinh(k.d) and the massless limit (decrement -> 1). Deterministic, in-browser, no API/key/network/AI.
Open it inside GDBS to save runs to Sandbox, attach results to a Worklog case, or share through a Gate client portal - all in the browser, nothing uploaded to anyone’s cloud.