A generic term for the supply and use of water and allied services to buildings/sites falling into three main categories, water in, water out and rain-water handling. Care should be taken in accepting the term water installations as there are there different traditions for the presentation of these services between countries and also various methodologies common to specific industries. This may mean that the figures may be split and represented in different parts of the schedule of works but of course the total sum will be the same just the apportionment and allocation will change. Water in may generally be considered the supply from the supply authority to the building so may be presented as a connection charge to the supply meter (the meter usually remaining the property of the supply company). Secondly water in would including supply (from the meter) pipework and storage of potable water (or not in the case of a rising main installation) plus the delivery to the user taps or connections the totality of which represents water in. Water out is the routing from the installations to the drain or sewers of the waste water and would include ventilation and traps to exclude the ingress of foul air. Water out includes all pipework and ducting but excludes sanitary fittings etc. Current Eco consideration may differentiate between W.C. water and ‘grey water’ which may have a secondary use for garden irrigation etc. Rainwater and associated fittings may in some traditions be shown in water installations but may appear under the heading of roof in others. Likewise rainwater harvesting (a current trend to capture rainwater for re-use) may encompass storage, handling and systems, often but not exclusively considered as part of the water out installations. A/C condensate water drainage, in the case of circulated chilled water would be included in water out as it feeds to the drains, though it is very suitable for grey water purposes. It is therefore very important to understand under which categories or headings each component function and costs are being presented. In the figures presents on the detailed costing schedules for each presented model the split and apportionment of such items should be obvious such as the case of the DIN standard which is at variance from the UK BCIS system.