The minimum requirement for a single-tier mezzanine floor is a suitable ground concrete floor slab to support the post loads and at least 2.1 metres of head clearance above and below the deck of the mezzanine. To achieve these non-habitable area clearances, we recommend a minimum roof height of at least 4.5 metres. Suitable access, such as a staircase, and adequate fall protection in the form of guardrails fitted to all exposed floor edges are also a must.