What's the minimum size for a house slab?

There’s no genuine fixed minimum — your slab is sized to match your building’s footprint, whatever that footprint genuinely is, from a compact granny flat through to a large family home.

Very small slabs can sometimes carry proportionally higher costs per square metre, since certain fixed costs (site setup, minimum labour, minimum concrete truck quantities) don’t scale down linearly with a smaller area.

Rather than a minimum size threshold, the genuinely relevant question is whether your specific building design and its actual footprint have been properly assessed and quoted for — size itself isn’t the limiting factor.

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