The problem: floor space full, hall half empty
A typical scenario among German SMEs: the storage space is no longer sufficient, yet only 40–50 % of the existing hall volume is actually used. The space above the racking stays empty. A new hall build costs 600–1.500 EUR/m² and takes 12–24 months. Relocating means business interruption. The solution: mezzanines (storage platforms), a second or third level within the existing hall.
Mezzanine vs multi-tier installation: what is the difference?
Mezzanine (steel platform / storage platform)
A self-supporting steel structure that inserts a continuous level into the hall. Modular design with spans of up to 10 m without intermediate columns. The use of the space below and on top of the platform is entirely flexible: racking, workstations, picking zones.
Multi-tier installation (multi-tier shelving)
Here the shelving itself forms the load-bearing structure. Walkways and intermediate floors are suspended within the shelving installation. Ideal when the entire area is to be used as shelf storage. Up to 3 levels can be realised on top of each other.
How much load can a mezzanine carry?
| Load class | Load capacity | Application |
|---|---|---|
| Light | 250 kg/m² | Small parts, office areas |
| Medium | 350 kg/m² | Shelf racking |
| Standard | 500 kg/m² | Industrial warehouses |
| Heavy | 750 kg/m² | Heavy stored goods |
| Heavy duty | 1.000–1.500 kg/m² | Pallet storage on the platform |
Do I need a building permit?
The answer is: it depends, namely on the federal state. Mezzanines inside existing buildings are generally regarded as items of equipment. However, as soon as escape routes run across the platform or it accommodates occupied rooms, building-regulation requirements apply.
Examples:
- Brandenburg: rack storage up to 8 m (top edge of stored goods) permit-free
- Hamburg: racking installations up to 12 m inside buildings permit-free
- Hesse: no exemption for racking
Recommendation: always coordinate in advance with the responsible building control authority and a fire protection specialist planner.
Fire protection: what you need to consider
Fire protection is often the most demanding aspect of a mezzanine:
- From a stored goods height of 7,5 m: automatic fire extinguishing system (sprinklers) mandatory
- With sprinklers: fire compartment area of up to 10.000 m² without fire resistance requirements for structural components
- Without sprinklers: max. 1.800 m² fire compartment area
- Escape route length: typically 35–50 m depending on the safety category
- Steel structures: F 0 without coating, F 30 to F 90 achievable with intumescent coating
Safety equipment: what the standard requires
According to DIN EN ISO 14122 and occupational health and safety law:
- Guard rails: mandatory from a fall height of 1 m, minimum height 1,10 m, with knee rail and toe board (10 cm)
- Stairs: minimum width 800 mm, step formula 600 ≤ g + 2h ≤ 660 mm
- Pallet transfer gates: self-closing as fall protection, double-gate system (one gate open = the other closed)
Materials handling: how do the goods get upstairs?
- Goods lift / platform lift: electro-hydraulic or scissor lift, for pallets and heavy goods
- Spiral chute: gravity conveyor for packaged unit loads on the way down, compact and cost-efficient
- Conveyor belts: for high throughput in order picking
- Pallet transfer gates: integrated into the guard rail for forklift loading
What does a mezzanine cost? The cost calculation
| Item | Costs (net) |
|---|---|
| Mezzanine from the catalogue (excluding installation) | 70–89 EUR/m² |
| Complete incl. stairs, guard rails, installation | 150–300 EUR/m² |
| Heavy duty / special construction | 300–500 EUR/m² |
Sample calculation: 400 m² mezzanine
| Item | Costs |
|---|---|
| Platform 400 m² × 200 EUR/m² (incl. installation) | 80.000 EUR |
| Goods lift / platform lift | 8.000–15.000 EUR |
| Structural analysis + permit | 3.000–5.000 EUR |
| Total | approx. 91.000–100.000 EUR |
Comparison with the alternatives
| Alternative | Costs | Timeframe |
|---|---|---|
| Mezzanine 400 m² | 91.000–100.000 EUR | 4–8 weeks |
| Hall extension 400 m² | 240.000–360.000 EUR | 6–12 months |
| New build 400 m² | 320.000–600.000 EUR | 12–24 months |
Payback: when does the platform pay for itself?
At commercial warehouse rents of 4–8 EUR/m²/month, a 400 m² platform saves around 19.200–38.400 EUR per year in rental costs. The payback period is therefore 2,5–5 years, not counting avoided relocation costs and with no additional heating or energy costs, since the existing hall is used.
Conclusion: the smartest way to grow
A mezzanine is the fastest, most economical and lowest-risk way to turn idle hall volume into productive storage space. It can be implemented within 4–8 weeks, at a fraction of the cost of a new build, without interrupting operations.