Our 1930s house was re-wired by the previous owners, but there are very few sockets around the house. In most of the rooms (excluding the kitchen), there are only one or two sockets, so we have four- and six-socket extension leads everywhere which are in permanent use for various different appliances. Obviously this is unsightly, and we have rugs and masking tape around the place to avoid accidental trips - but from an electrical point of view, is there anything inherently unsafe in using multi-socket extension leads on an ongoing basis?