Correct option is C
Cavity Wall:
A cavity wall consists of two parallel walls (an inner and outer leaf) separated by an air gap or cavity.
This design improves the wall's performance in terms of insulation and protection from environmental factors.
Benefits of Cavity Walls:
Sound Insulation: The air gap acts as a barrier to sound waves, reducing noise transmission.
Heat Insulation: The cavity reduces heat transfer, maintaining thermal comfort inside the building.
Prevention of Dampness: The cavity prevents water penetration from the outer wall to the inner wall, keeping the interior dry.
