Water-saving features in Dutch housing, 1993-1998
The use of water-saving features during new building and renovation is on the increase. These mainly consist of showerheads, lavatory flushes and flow regulators in taps.
| 1993 | 1994-1995 | 1995-1996 | 1996-1997 | 1998 | Environmental target for construction, 1995 | |
| % completed dwellings | ||||||
| Water-efficient showerhead | ||||||
| Renovated housing | 30 | 41 | 33 | 47 | 63 | 50 |
| New building | 36 | 42 | 61 | 54 | 47 | 50 |
| Flow regulators | ||||||
| Renovated housing | 7 | 22 | 18 | 30 | 37 | 50 |
| New building | 19 | 14 | 41 | 40 | 57 | 50 |
| Water-efficient toilet flush | ||||||
| Renovated housing | 71 | 74 | 66 | 96 | 91 | 30 |
| New building | 95 | 95 | 96 | 95 | 98 | 100 |
| Water-efficient toilet | ||||||
| Renovated housing | 33 | 30 | 21 | 22 | 38 | |
| New building | 25 | 45 | 43 | 35 | 47 | |
| Source: BMT. | RIVM/EDC/Oct02/0410 | |||||
Water-saving features in ever-wider use
The housing construction sector used water-saving features more and more in the period 1993-1998. The application of water-saving features in new building and renovation projects is important if structural water savings are to be achieved.
The use of water-efficient showerheads is increasing in the residential construction sector. The level of introduction in 1998 matched the environmental target. Almost all houses now have showers. More than 40% have a water-efficient showerhead (NIPO, 2001).
Flow regulators are being installed more and more often. However, the table above shows that the objective was not met in 1998.
Water-efficient toilet flushes are now largely standard fittings in new housing and large-scale renovation projects. More than 20% of homes have low-capacity toilet flushes (NIPO, 2001).
Water-saving objectives in new building and renovation projects
In early 1992, the Ministry of Housing, Spatial Planning and the Environment submitted the Water-Savings Action Plan (Actieplan Waterbesparing) to the Lower House (VROM, 1992). In the plan, the minister points out that, in the next 20 years, the increase in water consumption needs to be halved at least. In the Drinking and Industrial Water Supply Policy Plan (Beleidsplan Drink- en Industriewatervoorziening - VROM, 1993a; VROM, 1995), the water-savings policy took definite shape. Because major water savings can be achieved using the relevant features in housing (such as showers and toilets), a link was made with the activities of building and engineering companies.
The Environmental Council for the Construction Industry has, as part of the Construction Environmental Targets 1995, listed the target percentages for water savings set out in the table (VROM, 1993b). However, no environmental target has been set for the use of water-efficient toilet flushes.
In addition to a "zero measurement" for 1993, it was agreed that periodical measurements would be conducted of penetration levels. The usable results have been included in the table.
Showerheads, cisterns and flow regulators
Higher resistance in the showerhead means that a water-efficient showerhead lets water pass through less quickly than an ordinary showerhead. The amounts for both types depend on the warm-water system. The average flow through a water-efficient showerhead is 7.5 litres a minute; the difference with the non-efficient showerhead is approximately 0.5 litres per minute.
The type of cistern used for toilets has a considerable effect on water consumption. The water-efficient toilet results in less water being used to flush the toilet, either because of the smaller capacity of the cistern and/or because of the installation of a 'dual flush' system, sometimes in conjunction with a different shape of the toilet. With this form of water-saving, the maximum cistern volume is assumed to be 6 litres.
Flow regulators and aerators are generally used in sink taps. A flow regulator reduces the water flow by reducing the diameter in the water pipe. An aerator is a part fitted onto the tap that adds air to the water so that the water flow is reduced.
References
- BMT (1999). Vijfde penetratiegraadmeting van waterbesparende voorzieningen in de woningbouw. BMT Management en marketingadviseurs, Utrecht.
- NIPO (2001). Het waterverbruik thuis 2001. NIPO, A8324, December 2001.
- VROM (1992). Waterbesparing Tweede kamer, 1991-1992, 22556, no. 1. Ministry of Housing, Spatial Planning and the Environment, The Hague.
- VROM (1993a). Beleidsplan drink- en industriewatervoorziening. Deel 1, Ontwerp planologische kernbeslissing. Sdu Uitgeverij, The Hague.
- VROM (1993b). Beleidsverklaring Milieutaakstellingen Bouw 1995. Ministry of Housing, Spatial Planning and the Environment, The Hague.
- VROM (1995). Beleidsplan drink- en industriewatervoorziening. Deel 3, Kabinetsstandpunt. Sdu Uitgeverij, The Hague.
Relevant sections and indicators in the Environmental Data Compendium
- Household water consumption per capita in the Netherlands, 1980-2001
- Housing stock, investment and newly constructed housing in the Netherlands, 1980-2002
Relevant information outside of the Environmental Data Compendium
- Mülschlegel, J.H.C. and F.J. Kragt (1998). Waterwinning en waterverbruik bij doelgroepen. RIVM (report no. 703 717 003), Bilthoven.
- Crommentuijn, L.E.M. and E.D.M. Verbeek (1999). Prognose milieueffecten Duurzaam Bouwen. RIVM (report no. 771 404 002), Bilthoven.
