Understanding UK Mezzanine Floor Regulations

Mezzanine floors are a practical and cost-effective way to maximise space within commercial and industrial buildings — from warehouses to retail units. But before planning your installation, it’s essential to understand the relevant UK regulations that apply.

At Equip, we’ve helped businesses across the UK design, manufacture and install mezzanine floors that meet all structural and regulatory requirements. In this guide, we’ll break down the key compliance factors so you can move forward with confidence.

Do You Need Planning Permission for a Mezzanine Floor?

In many cases, planning permission is not required for a mezzanine floor, especially if:

• It is self-contained within an existing building 
• It does not change the exterior appearance of the building 
• There is no significant change in use (e.g. from storage to office) 

However, planning permission may be required if the mezzanine increases floor area by more than 200 square metres, particularly in retail spaces, or if external alterations are involved. It’s always best to consult your local planning authority early in the design stage.

What Building Regulations Apply to Mezzanine Floors?

Regardless of planning permission, all mezzanine floors must comply with UK Building Regulations. These regulations focus on:

• Structural integrity (Part A): Ensuring the floor is safely supported 
• Fire safety (Part B): Including fire exits, escape routes, alarms, and in some cases, sprinkler systems 
• Accessibility (Part M): Providing safe and suitable access for all users 
• Ventilation and lighting (Part F and L): Depending on intended use 

A Building Control application will need to be submitted either through the local authority or an approved inspector, and the mezzanine must pass inspection before being used.

What Are the Minimum Requirements for a Mezzanine Floor?

Minimum requirements can vary depending on the floor’s purpose (e.g. office, storage, or production), but common considerations include:

• Headroom: Typically at least 2 metres beneath and above the mezzanine 
• Load-bearing capacity: Must be calculated based on usage (see more below) 
• Handrails and balustrades: Required on exposed edges 
• Fire protection: Depending on floor size, usage, and occupancy 
• Safe access: Via stairs or access equipment compliant with regulations 

mezzanine floor in cafe

How Much Weight Can a Mezzanine Floor Take?

Load-bearing capacity depends on the design, materials, and use case. Typical design loads include:

• Storage mezzanines: 3.5 to 7.5 kN/m² (kilonewtons per square metre) 
• Office mezzanines: 2.5 to 4.0 kN/m² 

Structural engineers must calculate the floor’s load capacity during the design phase to ensure it meets safety standards.

How Thick Should a Mezzanine Floor Be?

Mezzanine floor thickness depends on the joist depth, decking material, and load requirements. A typical structural depth ranges from:

• 150 mm to 400 mm — depending on span and load 
• Decking thickness: Generally 38 mm (e.g. particle board, ply, or metal decking) 

Design calculations should be tailored to your building and usage needs.

What Size Joists Are Required?

Joist size is based on span, spacing, and load:

• For small spans under 3m, joists may be 150 mm deep 
• Larger spans (up to 6m) may require joists 250 mm or more in depth 
• Steel sections (e.g. RSJs or purlins) are typically used in industrial settings 

An engineer will determine the correct specification based on detailed loading and design requirements.

Are There Limitations on Mezzanine Floors?

Yes — several limitations may apply:

• Fire protection: Floors over 400 m² or multiple levels may require full fire-rated enclosures and sprinkler systems 
• Headroom: Insufficient headroom can make areas unusable or non-compliant 
• Support structure: Columns may interfere with workflow or space usage 
• Building use: Some change-of-use mezzanines may trigger planning restrictions 
• Retail settings: Retail mezzanine floors over 200 m² often require planning permission 

Stay Compliant From the Start

Mezzanine floors can transform the functionality of your building, but only when installed in line with UK regulations. From planning permission to structural engineering and Building Control approval, there are several compliance hurdles to navigate.

At Equip, we help businesses at every stage of the process, offering advice, design, manufacturing, and full installation of mezzanine floors tailored to your site and industry. Our experience ensures that every solution meets safety and regulatory standards while maximising usable space.

If you’re considering a mezzanine floor for your business, get in touch with our team today to ensure a compliant and cost-effective result.