Marble is an aesthetically appealing and thermodynamically ‘cool’ building material. However, when subject to weathering, marble building facade elements undergo surface degradation that result in changes to appearance and optical properties. These changes impact both the aesthetics and the thermal characteristics of the marble. This chapter highlights an experimental approach for the characterization of these changes, and numerical simulations for studying the corresponding impact on building energy performance when marble is used as an envelope finishing layer. Optical characteristics studied include gloss, solar reflectance, transmittance and absorbance. Changes in the optical characteristics of marble are used to assess the effect of degradation on it’s thermal properties.