Behind the figures

Behind the figures

Water efficient products are becoming increasingly common, but how easy is it to actually quantify what savings are being made and where should installers be looking to find out about designing bathrooms that significantly reduce consumption?
In order to be able to effectively design more water-efficient bathrooms, it is essential that installers become familiar with the way in which water consumption in a property is officially measured. By assessing ‘average’ usage across all bathroom facilities (as well as the water use from appliances such as washing machines and dishwashers), it is possible to begin to create a fairly accurate understanding of the total consumption of a property.
From these findings, it is then possible for the installer to identify the ways in which the customer can become more efficient in terms of their usage – either through the installation of better products or through education. Changing people’s behaviour and habits can prove difficult, therefore encouraging the adoption of more efficient sanitaryware is a simpler and more effective approach.
Setting a benchmark
Recognising the need to lower water consumption throughout UK homes, Part G of the Building Regulation was introduced in 2010 to set out new guidelines. One of the key changes was the inclusion of Regulation 17K – Water efficiency of new dwellings. This policy applies to new build homes and focuses on permitted daily water usage, setting the maximum allowance at 125 litres per person per day. Considering the accepted average usage is currently 150 litres, this new regulation highlighted a clear movement towards a change in approach around water consumption.
In a similar move, the Code for Sustainable Homes also places increased emphasis on reduced water usage. The attainment of each level is reliant on meeting the required specifications – in much the same way as it is for energy use.
For example, in order to be classified as Level 3/4, the property must use less than 105 litres per day, similarly, to achieve Level 5/6, the limit is set at 80 litres per day.
While these standards are set out for new homes, they also provide useful guidelines for installers when approaching a retrofit installation. Aiming to emulate the performance of a Level 4 property under Code for Sustainable Homes or working to the Part G stipulations will ensure that the bathroom is not wasting water and could actually lead to additional financial savings.
However, recent research suggests there is a general lack of awareness amongst many plumbers and bathroom installers about the Part G regulations, despite their introduction more than two years ago. Add to this a growing cynicism about whether installations will actually be assessed and a clearer idea emerges of the difficulties associated with trying to highlight the concept of water efficient products.
The role, therefore, of manufacturers such as iflo has become to create products that can actually deliver the expected savings without the need for either behavioural change or great expense for the end user or to cause the installer to have to undertake more challenging installations.
For example, the iflo Rhea Suite, has a dual action flush and delayed inlet valve that provide water saving for the consumer, but also the cistern includes a reversible inlet valve and cistern plug giving more flexibility on installation.
In order to ascertain the official water usage statistics for a new property or, more specifically, a new bathroom installation, an approved water efficiency calculator must be used and the correct methodology (as set out in the Water efficiency calculator for new dwellings – Approved Document G, Requirement G2) must be adhered to.
Whilst this regulation only applies to new-build properties, by applying the same methodology to any new bathroom project, the installer can highlight how much the water consumption in the bathroom will be reduced.
There are a number of online water calculators that publish the methodology set out in the Water efficiency calculator for new dwellings document to help calculate the results. These include the Bathroom Manufacturers Association (www.thewatercalculator.org.uk) and Water Research Centre (http://sites.wrcplc.co.uk/partgcalculator).
The individual details from each specific product are entered into the calculator (See Table 1) to produce a figure for total litres of water consumed by each person per day. By adding together all of the relevant products, a total amount can be obtained.
In the case of new-build, it is necessary to submit the water efficiency results to the local authority for verification and approval. It should be noted that these online calculations are exactly the same methodology as used for calculating water consumption for the Code for Sustainable Homes.
Although designed specifically for new-build properties, in the case of a retrofit installation, employing this straightforward system can be a simple way to highlight to the customer that they are using an excessive amount of water with their current bathroom and explain how they can reduce usage with more efficient products.
While it should be noted that results will vary and any figures calculated should be used as approximations due to individual user behaviour, this methodical approach will give bathroom installers a better understanding of the advancements in technology and equip them with the knowledge to sell the products.
Using the system
As an example of how to utilise the calculator – and what savings can be made – the water usage of iflo’s new Rhea 6/4 litre flush Close Coupled WC pan can be compared against the traditional 9 litre flush Close Coupled WC (the most common type of existing single flush WC currently in UK homes).
By using the water calculator, it is evident that the daily saving from installing the iflo Rhea WC is over 19 litres per day. If additional data is factored in, a further estimate on average household water savings shows that this change of product could save 46 litres per day.
(NB Based on average number of people in UK household being 2.4)