28th May 2010

Playing a part

Still confused as to how Part G affects you, the retailer? Christian Taylor-Hamlin, technical director at the BMA, has the answers


Q What is Part G?

A Officially it is The Building Regulations 2000, Approved Document G, Hygiene.


Q What does it do?

A It details suitable methods of construction, for hygiene requirements to help the building industry comply with the requirements of the Building Regulations. Other approved documents deal with other aspects of buildings, for example Part H covers drainage, Part M covers access to and use of the building and Part F covers ventilation.


Q There seems to be a lot of fuss being made of the new Part G, what does it say that seems to be so controversial?

A The new Part G has introduced some fundamental changes with regard to water efficiency and hot water safety. For water efficiency, Part G introduces a prescribed calculation methodology that must be used as part of the planning permission application for all new dwellings. The calculation works by multiplying the measured water use of a product by a 'factor’ – based on usage – to give a litres per head per day value. Once all water using products have been calculated the total allowable design use is 125 litres per head per day.


Q Does this mean that people who buy new homes will not be able to get more than 125 litres each a day?

A No, it just means that the water using products fitted in the new dwellings have been optimised to deliver water while minimising any potential waste. Water savings are still as much about consumer attitude and behaviour as well as installing water efficient products. The water supply will not be cut off if you exceed the 125 litres per head per day and you will continue to be billed for your water on the normal basis, ie either rateable value of your home or via a water meter. It is also worth noting that all new homes are required to have water meters fitted and that this has been the case for some 10 years.


Q So what is the point of this calculation?

A The point is that the UK is becoming increasingly water stressed with some parts of the country being drier per capita than Abu Dhabi. The calculation is therefore one item in a series of measures initiated by the Government to reduce average water consumption. The Government has also pledged to raise the level of metering from the existing 30% to 90% within 10 years.


Q You also mentioned hot water safety – what are the changes for this bit?

A Part G now introduces the need to manage the maximum temperature of water discharged into baths in all new dwellings. The requirement is aimed at reducing bathtime scalds, which have traditionally accounted for around 20 deaths and 500 serious scald injuries each year. The requirement is that the temperature of the water filling the bath shall not exceed 48 ℃. This temperature has been identified as being hot enough for bathing but also providing enough time to escape from the hot water. The hotter the water the quicker that third degree burns occur.


Q How do you control the temperature?

A Part G allows the installation of any mechanism that can prevent temperatures in excess of 48℃ being delivered to the bath. However, it is recognised that the simplest and most cost effective method is to use a thermostatic mixing valve – TMV. The TMV mixes hot and cold water together to deliver water at a pre-determined set temperature. These devices can either be pre-set or user adjustable with a maximum temperature stop to prevent selection of temperatures in excess of 48℃. Best practice is to use TMVs approved under the BuildCert TMV2 scheme. More information can be found at TMV2 Approved Valves


Q So as a retailer how will all this affect me?

A The effect on retailers could be minimal however, this will depend on your typical customer base and potentially where in the country you live. If your customer base includes re-developers and self builders then knowledge of these requirements may help you to make that next sale. In addition, there are some planning authorities that, due to the level of water stress in their area, have more stringent requirements for water efficiency than those detailed within the new Part G. This again will affect the increasing demand for water-efficient products. As time goes by the need to understand water-efficient mechanisms like those detailed in Part G will increase, as more and more government initiatives start to impact this market.


Q So all this may be stopped by a change of government?

A No. All political parties have committed to environmental requirements to prevent climate change. This includes water efficiency and the latest links are save water, save energy, save carbon; saving water, in particular hot water, reduces the energy required to heat the water thus saving money on a metered water bill and on your energy bill. In addition to this the EU has placed demands on member states to reduce carbon emissions by 20% by 2020. Reducing water is an integral part of the UK meeting its carbon reduction commitments.


Q Where can I find more information or find out what products are water efficient.

A The Bathroom Manufacturers Association has training guides available for information on using TMVs and also has a live list of water efficient fittings.

Visit www.bathroom-association.org and www.water-efficiencylabel.org.uk