A plumber's life is varied. They may work on new buildings, or on the extension or maintenance of existing ones. They read plans to determine the layout of the system and measure and mark out where pipes will be installed, being mindful of other services such as electrical wiring, etc. Installation work includes central heating systems, sanitary systems and drainage systems. Heating systems may be powered using electricity, gas, oil, solid fuel or even solar energy. Maintenance work includes routine servicing and emergency repairs. The plumber uses a range of hand and power tools, which are used for cutting, bending and joining pipes.