The Shell value or S-value is an indicator that evaluates energetic qualities of the building envelope (the ‘Shell’), both gains and losses, equivalently relative to the form factor (efficiency of shape) of the house. 

That is to say, the S-value depends on the insulation, air tightness, influence of thermal conductivity (thermal bridges) and shape of the building, among other things. You can always find the current requirements at: https://www.energiesparen.be/EPB-pedia/eisen-per-aanvraagjaar 

Sintering involves heating grains of material to a temperature just below their melting point. This brings the grains closer together and creates more contact points, resulting in a very hard material. 

To make sintered bricks, the temperature in the brick kiln is raised to approximately 1125 degrees Celsius. The heat of the fire gives the bricks a beautiful greyish tint. 

Special bricks are bricks with unique shapes that provide a solution for creative design features. Special bricks enable you to build architectural shapes such as a 135° corner or a curved wall with a tight diameter using ready-made facing bricks.

With this bond, you are highlighting the vertical aspect of the brickwork. The facing bricks are laid one on top of the other so that both the horizontal ribbon joints and the vertical butt joints are continuous.