Two 1.5kW electric fires produce the same heat as one 3kW and are more
versatile.

Well, I've got several 3kW ones (and a couple of 2kW) and they're more
versatile than several 1.5kW ones. 3kW ones cost the same price as smaller
ones.

The main problem is with large kitchen appliances, which we can just plug in
where convenient without having to have special points put in, or
alternatively have to put up with inferior designs without built in heaters.

Christian.