Each field on a roof record is one of three things: pulled live from an open-data API, read from a static physics lookup, or computed from the two. Hover any box to trace its full ancestry.
material is fetched live from OS NGD, but "metal radiates at ε≈0.45" is a constant we look up (EMITT); that emittance and the albedo (from Sentinel-2) are balanced by the ASTM E1980 physics to give a roof’s modelled temperature. Nothing on a card is asserted; everything traces back to a source or a cited constant. The Radiative cooling line’s physics (the two-band sky, the ≈68 W/m² net flux, the 0.18 clear-sky duty) is reproducible in the radiative-cooling simulator.