We decided to have heat pump and air con installed and the chap who did it was outstanding, both in terms of workmanship and price.
His name is Mike, and the company is:
Northwest Airconditioning Ltd
145A Ashley Road
Hale
Altrincham
Cheshire
WA14 2UN
Heat pump systems heat your house using heat extracted from the outside air. They can extract heat down to -15C and, in summer, work in reverse to keep the house pleasantly cool. Cost: about the same a single double glazed window.