3.1. Fired clay bricks
Bricks are made by shaping a plastic mass of clay and water which is later solidifies by drying and firing. Bricks are among the oldest and most enduring of mankind’s building materials. They require a considerable amount of thermal energy during the firing process because they burn at temperatures of between 1000 and 1200◦C, depending on the clay type.
Light-coloured clays usually require higher firing temperatures than dark-coloured ones.This thermal energy amounts to 3.75–4.75 MJ per brick [47]. We applied an average value of 4.25 MJ per brick (standard size in Spain: 240 mm × 115 mm × 70 mm) for the comparison and computation of the energy content of buildings and masonry.