Re: Ring mains surely?
Yup the guideline for a 32A ring circuit is that it can serve up to 100 square meters of floor area. Obviously one needs to take into account the likely loading on the circuit, and also the impact of what would be affected should the circuit trip. A greater number of "smaller" circuits offeres better "discrimination" i.e. it contains the effects of a fault to the location of the fault with fewer unrelated items losing power.
For modern usage patterns its common for socket circuits to support a large number of very small loads (small appliances / electronic gadgets) festooned all over the place, and the occasional larger one. So ring circuits are well suited for the task. Kitchens / utility rooms often benefit from their own dedicated ring circuit where the concentration of larger "white goods" can use much of the capacity of a 7kW circuit quite easily.
So a good compromise for many places is one ring circuit per storey, plus a separate one for the kitchen. Plus additional dedicated radial circuits for individual high load items like cookers and hobs etc.