ST IVES plumbing and heating engineers Rule and Parker last week celebrated 41 years in business. The company, founded in 1968 by Frank Rule and Barry Parker, has grown over the decades and now employs around fifty staff to provide central heating systems to homes and businesses across East Anglia. Rule and Parker has had premises in West Street, St Ives, for over 25 years. Over the years the business has diversified, combining work for private domestic clients with large-scale projects for authorities such as South Cambridgeshire Council and Fenland District Councils. Mr Rule said the industry had changed hugely over the years, especially with the move to greener technologies. "In 1968, solid fuel and oil central heating were the new forms of heating, and now it's the energy efficiency products like solar hot water and air source heat pumps that are becoming very popular.