- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 09 Nov 2018
The number of storeys is determined according to the diagram below:
[Image source: Approved Document B2, ‘Fire safety: Buildings other than dwellinghouses’]
- Access and circulation.
- Fire safety and evacuation.
- Structural design.
- External air movement.
- Shading, views and right to light.
- Construction methods.
- Access for maintenance and cleaning.
Classifications of multi-storey buildings include:
- Low-rise: a building which is not tall enough to be classified as high-rise.
- Mid-rise: buildings of five to ten storeys, equipped with lifts.
- High-rise: more than 7 to 10 storeys.
- Skyscraper: 40 storeys or more.
- Supertall: exceeding 300 m.
- Megatall: exceeding 600 m.
 Structural types
The basic types of multi-storey structure (which may be used in combination) include:
Bracing is used to give stability so that columns can be designed as pure compression members. The beams and columns that form the frame carry vertical loads, and the bracing system carries the lateral loads. Braced frames reduce lateral displacement, as well as the bending moment in columns, they are economical, easily erected and have the design flexibility to create the strength and stiffness required.
Also known as ‘tube-in-tube’ and consists of a core tube inside the structure which holds services such as utilities and lifts, as well as a tube system on the exterior. The inner and outer tubes interact horizontally as the shear and flexural components of a wall-frame structure.
 Related articles on Designing Buildings Wiki
- Braced frame structure.
- Concept structural design of buildings.
- High-rise building.
- Multi-storey car park.
- Shear wall.
- Shell and core.
- Single-storey building definition.
- Skeleton frame.
- Structural engineer.
- Structural principles.
- Tall building.
- Tube structural system.
- Types of building.
- Types of structural load.
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