House Builders to Face Water Shortage from April

No, not the early onset of a hot summer this year, but another Government measure to continue turning us green. April 6th sees the latest amendment to the Building Regulations coming into force – Part G, Sanitation, Hot Water Safety & Water.

No, not the early onset of a hot summer this year, but another Government measure to continue turning us green.  April 6th sees the latest amendment to the Building Regulations coming into force in the form of Part G – Sanitation, Hot Water Safety and Water Efficiency.  Although there are changes through out the document, it is the last part which will be of particular interest to house builders.  For the first time, these regulations will limit the designed water use in newly built dwellings, although the important point here is that it is the theoretical use and not what will actually be used by the home owner that is controlled.

Official statistics say that currently the average amount of water used in British households is 150 litres per person per day (l/p/d), which in most cases is wholesome (potable) water supplied by the water companies and purchased by the occupants.  The new standard will compel new dwellings to be constructed so that the design usage is reduced to 125 l/p/d, although this is still higher than the Code for Sustainable Homes Level 3 requirement of 105 l/p/d or Level 5 requirement of 80 l/p/d.

The flushing of WC’s and the taking of showers and baths are obvious users of large amounts of water and these are targets of the new regulations, but so too are dishwashers, washing machines and the flow capacities of taps.  It is not the intent of the regulations to lower standards of hygiene, but merely to reduce the amount of water used during the processes.  Housing designers like us at BRD Tech, will be able to obtain an approved water use calculator to assess designs and make appropriate specifications, so expect to see such things as smaller baths, dual flush low flow WC’s and spray head taps.  Power showers may be particularly difficult to justify and to incorporate one or more of these into a design may well need a more innovative solution.

One way of supplementing the amount of wholesome water used, to incorporate higher water using features without busting the 125 l/p/d limit would be to install a rainwater harvesting system.  These systems catch, filter and store rainwater which falls upon the roof of the building.  This water is pumped back into the building and used for flushing the WC’s.  Harvested water can also be used in the garden and is even suitable for washing machines if desired.  Any harvested rainwater used is additional to the 125 l/p/d limit of potable water, so wholesome water not used for WC flushing can be allocated elsewhere -  your super turbo skin flaying power shower perhaps?  Rainwater harvesting is not essential at this stage, but other compromises may be needed to avoid it.  It should also be bourn in mind that rain water is free, offsets the amount of water you buy in and lowers your carbon footprint.

If you are not the designer, your main concern may well lay with the choosing of sanitaryware and fittings to go in the new home.  Beware, danger lurks here.  Do not be seduced by the exquisite Italian designer shower head that pumps out 25 litres of water per minute at 3 bar of pressure if your design only has capacity for an 8 litre per minute drizzle.  You can always sell it on E Bay if the Building Inspector makes you take it out.

Hopefully the new standard will not be too taxing for those who take the time to understand the requirements and can allow for it early enough in the design process.  To try to retrofit compliance at Completion stage will only result in disappointment and additional cost.  Government, who ever it may be when you read this, are concerned with the future supply of water and are keen to husband this valuable resource.  The lower use rates mentioned earlier are currently the voluntary standards of the Code for Sustainable Homes, but it is very likely that these will become mandatory in future revisions of the Building Regulations.