Swiss™

Represents the amount of solar energy absorbed by the roof. A value of 0 indicates that none of the solar radiation is absorbed, whilst a value of 1 indicates that a roof absorbs 100% of solar radiation.

Material’s capacity to release absorbed energy, expressed as a ratio between 0 and 1. The higher the emittance, the lower the surface temperature is. Nearly all non-metallic surfaces have high thermal emittance that helps them cool down.

A measure of the solar absorptance and emittance. The higher the SRI, the cooler the roof will be in the sun.

The density of a LUTUM roof causes them to heat

up more slowly during the day and return heat

BCA employed Solar Absorptance as a primary guide for colour classification, referred to as Light (L < 0.40),

Medium (M < 0.60), and Dark (D > 0.60). BCA

classification is correct at the time of writing but

may be subject to change. Check your local

state building regulations at the time of your

project.