Note: electric slab heating is a greenhouse-intensive technology.
In-slab heating systems are hot water pipes or electric wires or mats laid in a concrete slab or a concrete topping to a slab to provide heating to living spaces. They do not include on-floor heating systems laid over a slab under tiles or carpet.
Insulation is required at the edge of all slabs with in-slab heating system and underneath any suspended slabs (in all climate zones) to ensure heat is delivered only upwards to the living space and does not leak out of the edge or underside of the slab into the subfloor and/or ground.
The above insulation requirements only apply to concrete slab on ground construction or suspended concrete slabs above a subfloor. A suspended slab above habitable rooms or another dwelling is not one of these floor types and is not regulated by BASIX.