How much KVa is needed to run a house and workshop?

A really good electrician once told me that an average 3 bedroom house has a peak energy requirement of 12-15 kilowatts. That was 30 years ago and before energy saving appliances, compact fluorescent bulbs and much more efficient LCD and LED TVs. The biggest consumers of electricity are electric clothes dryers and any other heat source that uses electricity, microwave ovens, air conditioning and refrigeration. Today peak consumption could easily be kept under 7 kilowatts, even with a small and intermittently used workshop.