Planning permission
Works carried out inside a building usually do not need planning permission. The main exception is retail: in England, installing a mezzanine in a shop that adds more than 200 m² of floorspace for retail sale counts as development and needs planning permission. Changes to the outside of the building, or a change of use, may also need permission.
Building regulations
A mezzanine adds a new floor, so it is building work. Building control will look at:
- Structure - the frame, the decking and the loads on the existing slab
- Fire safety - fire resistance of the steel, and whether the mezzanine is open or enclosed
- Means of escape - travel distances, number of stairs and their width
- Guarding and stairs - balustrade heights and stair design to Approved Document K
Fire protection
Depending on the size of the mezzanine, its use and the escape routes, the steelwork may need fire protection - typically intumescent coating or board. Smaller open mezzanines used for storage often need less. Your fire engineer or building control body decides.
Loads
The floor is designed for its use, such as office, light storage or heavy storage. The engineer also checks the existing ground slab under each column; sometimes new pad foundations are needed. Our mezzanine load calculator helps you plan the numbers before the design.
Your landlord
If you lease the building, you will normally need the landlord's consent before installing a mezzanine.
General information for England, not legal advice. Check with your local planning authority and building control.