To allow the free passage of air in and around buildings to maintain the health of the occupants and the building itself by helping to keep it dry from the effects of condensation.
Use terracotta air bricks to match and to complement the colour of the exterior envelope of a building constructed from brick or stone. As a building weathers then the terracotta air bricks will weather, complementing one another more over time.
Ventilation terminals should be used on redundant flues only to help ventilate the flue way and to prevent rainwater entry. They are installed into the top of a flat topped chimney pot.