Sizing of RCBO

Further to that 100m2 per 30A circuit rule of thumb,  if the area served includes a garden, then the figures need a bit of modification. Adding a socket for the lawn mower may in a sense add an extra few hundred square metres to the area served, but the load does not scale.
Note that sometimes it is preferable to avoid a 'one out- all out' tripping situation, and there may need to  be more circuits than load estimates alone would require, so that not all of it is lost if there is a fault on one segment. This is especially true if some of the loads are 'dirty' and my cause other loads to suffer from voltage drops( flickering/"brown out") In that case dedicated sockets for expensive computers may be separate from the general ones, if they may be used by the industrial cleaners,  gardeners hedge clippers, or anything that looks like a welding bay ;-)
Note that in a modern building you do not need that many hundred watts per square metre before it starts to heat  uncomfortably,  and offices with lots of kit may actually need cooling rather than heating.
Mike

Further to that 100m2 per 30A circuit rule of thumb,  if the area served includes a garden, then the figures need a bit of modification. Adding a socket for the lawn mower may in a sense add an extra few hundred square metres to the area served, but the load does not scale.
Note that sometimes it is preferable to avoid a 'one out- all out' tripping situation, and there may need to  be more circuits than load estimates alone would require, so that not all of it is lost if there is a fault on one segment. This is especially true if some of the loads are 'dirty' and my cause other loads to suffer from voltage drops( flickering/"brown out") In that case dedicated sockets for expensive computers may be separate from the general ones, if they may be used by the industrial cleaners,  gardeners hedge clippers, or anything that looks like a welding bay ;-)
Note that in a modern building you do not need that many hundred watts per square metre before it starts to heat  uncomfortably,  and offices with lots of kit may actually need cooling rather than heating.
Mike