This Code of Practice applies to water supply installations connected to public or private water supply systems or to smaller private systems. The functional requirements of this Code also applies to rainwater installations, which are part of the pipe system supplying toilets and washing machines with rainwater from a tank or a similar container. Rainwater supply systems shall be designed according to "Rørcenter-anvisning 003. Use of rainwater to toilets and washing machines in dwellings". The code applies to both new installations and to improvements and additions to existing systems. Repair of pipes and minor alterations such as replacement of sanitary equipment, fittings, apparatus, containers, etc., can be made with materials and according to methods that were allowed at the time of the existing installation. The water supply installation covers installations in buildings and in the ground within the site.