Wet underfloor heating uses heated water to circulate through suitable polyethene barrier piping with separate circuits for different zones within the property. The traditional water-based system is costly to install as it involves removing the floor in an existing building. Hot water systems can increase floor height by at least 60mm due to the concrete screed that is required. Therefore, this form of UFH is most suitable for new homes or extensions where the systems can be installed during the building process. Wet underfloor heating systems use water for heating, so it can be linked to virtually any heat source from a standard boiler to newer sustainable technologies, such as solar thermal energy or heat pumps.