Mezzanine Floor Building Regulations: What to Know

A mezzanine is one of the cheapest ways to add usable floor space inside an existing building — but it's a structure, so it brings building regulations (and sometimes planning) into play. Here's what to know before you build.

Building regulations always apply

A mezzanine is a new floor, so it must be designed and built to the Building Regulations. The main areas are:

• Structure — the steel frame, columns, deck and connections must be designed for the intended loading (storage, office, retail) by an engineer, and fabricated to EN1090.
• Fire protection — depending on size, height and use, the steelwork may need fire protection and the mezzanine may need fire-rated construction.
• Means of escape — staircases, travel distances and sometimes a second means of escape are assessed against the number of people and the use.
• Access — stairs to the relevant standards, and in many cases provision for accessible access.

Fire is the big one

For larger mezzanines, or those used by the public or for offices, fire protection of the structure and proper means of escape are usually the deciding factors. Small storage platforms below certain thresholds can be simpler, but don't assume — it's assessed case by case.

Planning permission

Internal mezzanines often don't need planning permission, but there are exceptions (for example, significant increases in floor space in retail can). Check with your local authority if in doubt.

Getting it right

The practical route is: engineer designs the structure and the fire/escape strategy is agreed, then the steel mezzanine is fabricated to that design and installed. We design, fabricate and install mezzanine floors, staircases and access steel to suit — see mezzanine floors and steel staircases.

Frequently asked questions

Do I need building regs for a small storage mezzanine? It still needs to be structurally sound and compliant. Smaller, low-occupancy storage platforms can be simpler, but building regulations still govern the structure and access — get it assessed.

Does the steel need fire protection? Often yes, depending on size, height and use. It's one of the first things to establish, because it affects the whole design.

Can you handle design, fabrication and install? Yes — we design to the loading and fire requirements, fabricate to EN1090, and install. Tell us about your building for advice and a quote.