Which boiler to use may depend on the fuel that is available. Gas is the most popular choice, followed by oil, Liquid Petroleum gas (LPg) then solid fuel and finally electricity. LPG is a flexible, clean burning fuel, which, in some situations is cheaper to install than connecting to mains gas. Electricity can be expensive but this can be outweighed by its low installation costs.

It is the boiler, more than any other factor that determines the efficiency of the system. Switching from a conventional boiler to a condensing boiler, with around 97% efficiency, can make large savings in fuel but this has to be balanced against increased purchase costs. Combination boilers, which do away with the need for hot water cylinders and heat only the water that is used, are very popular with developers and builders of smaller houses. Many of them are not up to the job of providing hot water for a family house although boilers with a heatstore are now coming on to the market that can cope with the greater demand and handle more
than two outlets at any one time.

The plumber is also responsible for the installation and connection of sanitaryware. These items are normally supplied by the self builder and must be ordered in good time.