A basement storey is the lowest, often partially sunken part of a building that serves as a plinth or substructure. The basement storey typically protrudes slightly above ground level and forms the transition between the foundation and the ground floor. In architecture, the term also refers to the heavy, unadorned base of a facade or column.
Basement storey vs. cellar vs. semi-basement
| Term | Description | Position |
|---|---|---|
| **Basement storey** | Substructure of the building, partly above ground | Partially below, partially above street level |
| **Cellar** | Fully underground space | Entirely below ground level |
| **Semi-basement** | Half-sunken habitable floor with windows | Partly below ground, habitable |
Functions of a basement storey
- Structural — forms a stable base for the building and distributes loads to the foundation
- Moisture protection — raises the ground floor above ground level, reducing rising damp
- Storage — the space within the basement storey is often used for storage, building services or garages
- Aesthetic — a visible basement storey gives the building a monumental appearance
Architectural significance
In the classical orders (Doric, Ionic, Corinthian), the basement storey is the substructure on which columns or pilasters rest. It typically consists of:
- Plinth — the lowest, flat strip
- Basement proper — the main volume
- Cornice or water table — the upper moulding that sheds water
Basement storey and moisture issues
Because the basement storey sits partially in the ground, moisture management is essential:
- Waterproof coating — bitumen or plastic membrane on the exterior
- Drainage — a drainage pipe around the base of the basement storey
- Ventilation — adequate air circulation to prevent condensation
- Damp-proof course — a moisture barrier between the basement storey and the rising masonry
Related terms
- Semi-basement
- Strip foundation
- Plinth
- Skirting
- Classical orders
- Foundation wall