Hot Water 1

Topic 1. Domestic Hot Water 1: Using Less


Using less hot water can help you save around 15-30% of your energy bills, depending on the size of your premises and water consumption.

Energy is used to heat water and keep it warm, so using cold water as a first preference, and using hot water more efficiently means you will save energy and money.

Safe drinkable water is not easy to access on small islands and water treatment is expensive with a significant environmental impact. The water supply in the islands comes from a mixture of boreholes and wells, which are supported by a desalination plant. Despite having multiple sources, we don’t have an endless supply of drinking water. The demand for water is particularly high during events and the summer holidays. This is even more of a problem when we do not receive regular and prolonged rainfall.  Using less water will help to conserve the water supply on the islands.

Simple appliances like low flow taps and shower heads will enable you to reduce your hot water consumption, and therefore the proportion of your energy used to heat it. Below, we outline appliances for taps and shower heads, where to install them, how to use them, and how to encourage your guests to use them.

In many cases, a reduction in water use can be achieved by installing low cost and easy-to-fit devices to taps. As these fittings are low cost the payback is short. But when refurbishing washrooms, bear in mind that many water efficient taps are the same price as less efficient models.

 How They Work

Water-efficient shower heads: Showers are the single biggest user of water in an average home, using  25% of the total water consumption. New water-efficient shower heads use technology that can produce water flows that feel far higher than they actually are – an easy way to save both water and energy. Water pressure remains high due to either the water being pushed through smaller holes the shower head, or being mixed with air. The result is a high-pressure, low water use shower.

What is the right flow rate? Look for a shower head providing 6lt per minute or less.  According to the water and energy calculator, the average length of a shower is 7.5 minutes. At 8lt per minute thats 60 litres of hot water down the drain.

How much would a 6lt per minute shower head use for a standard shower? What about if the shower was just one minute shorter? Next time you have a shower try timing yourself and working out the total litres of hot water used. If you don’t know the flow rate of your current shower head you can work it out using the guidance below.

Electric Showers: Low flow shower heads are not recommended for electric shower units. There are two reasons for this; the unit may be damaged by using a low flow head, and the showers are already low flow. Electric shower units have to quickly heat water up to around 40 degrees for showering, to help them do this they generally already provide a reduced flow rate.

Tap aerators and flow regulators: If you’re not replacing taps or shower units, you can fit flow regulators to showers and aerators to taps. Flow devices are easy to install. They often contain precision-made holes, filters or flow aerators

Tap aerators: Key considerations for installing:

  • The aerator is a small attachment that either fits onto the end of the tap, or can be inserted inside the existing spout.
  • Correct installation is important – a poorly fitted device or control system can increase water use.
  • Perception is often a barrier – water efficient taps and retrofit devices are just as effective for hand washing if installed correctly.

When flow regulation devices are installed correctly, they should not compromise performance.

Kitchen taps:  Dual-flow taps are available for kitchens, so you can choose to have a standard or reduced flow according to your needs. 

Activity: Check your flow rate

Do you know the flow rate of your taps and showers? Most people do not and there is no easy way to find out without physically measuring the flow over a period of time. You can easily find out, using a bucket (with litres marked) and stop watch.

  • Taps: A flow rate of between 4 and 6 litres/minute is generally regarded as ‘efficient’ or good practice and is adequate for hand washing.
  • Showers: A flow rate of around 8l per minute is considered efficient practice but some showerheads are even lower than this.

Activity: Try out a low flow shower head

You can borrow a low flow showerhead from Ben Robbins ( Depending on your current shower head, it should be fairly easy to unscrew the current head and screw on this one.

Which has recently reviewed water saving shower heads and put the details into a comparison site:

Liz who tried out the showerhead said that ‘ I was a bit dubious, but it was a very good shower experience, and well worth making the switch!’

 Activity: Fill out the Water Energy Calculator. This tool concentrates on your home, not your business, but is still a useful learning tool for understanding energy and water use in buildings. Find the calculator here, or jump straight to reading their report into the results.

Next Steps

1  Check the flow rate of your taps and showers

2  Research or ask a plumber or supplier the following questions:

-which kinds of flow regulators / tap aerators would be suitable for your:

  • Shower heads [you can try out a low flow shower head]
  • Bathroom taps
  • Kitchen taps
  • Any fittings to the mains water supply need to comply with the Water Supply (Water Fittings) Regulations 1999.4
  • Will regular maintenance be required to ensure the tap is operating effectively? For example, soap deposits or scale build-up can cause tap mechanisms to jam (in particular, some push-down taps), resulting in taps dripping.
  • Is the maintenance something you can do yourself? In most cases it will be.

3  Do you want to fit it yourself? You may find an instruction video on YouTube which will show you how to install a new shower head or tap aerator

4  Look for replacements and try to get the lowest flow rate you can

5  Once fitted, you can check if the flow rate is reduced by using a bucket and timer again!

6  Ongoing maintenance: Check the manufacturer’s suggestions, and the plumber’s, to see if regular maintenance / checks will be necessary, and schedule this in.

Communicating With Guests

No-one likes to be told what to do, and most guests are tired of being asked to make what they might feel are token efforts to ‘save the environment’. So here are some tips to encourage your guests to help you achieve your energy efficiency goals.

  • Communicate what you’re doing and why, your goals and what you’ve achieved already. Make it easy for them to help you achieve your goals, and show guests what, collectively, you’ve been able to achieve. for example you could work out the total litres of hot water saved in a typical week through having low flow shower heads and include this information in your welcome pack.
  • Cost is not necessarily the best motivator to encourage guests to save water. They have, after all, already paid for their stay. Instead, show the energy and water implications of reducing hot water consumption, such as linking to the bigger pictures such as helping to preserve the natural beauty of the Isles of Scilly.For generations the people of Scilly have worked in tune with soil and sea, following a tradition of self-sufficiency and innovation, borne of isolation and necessity. Outstandingly beautiful, uncrowded and unspoilt, the islands seem like a world apart from everyday life. Above all, they give our visitors the space and freedom to do everything – or next to nothing – in a breath-taking location that enjoys the mildest climate in the UK.Demonstrating care over the use of energy and water, and reducing waste will reflect to visitors that islanders care about their unique environment which receives the UK’s and Europe’s highest levels of environmental protection possible – including 27 Sites of Special Scientific Interest as well as 11 out of the 50 Marine Conservation Zones around England.
  • Make it specific to the Isles of Scilly, or your specific island. For example, you could include: ‘On the Isles of Scilly your water is supplied from a mixture of borehole sources and a desalination plant (St Mary’s), with a small amount of rainwater harvesting[1]. As an island community, we ask you to join us, and other guests, in using this resource carefully, to preserve our aquifers, and reduce our energy consumption’.
  • Be consistent. If you’re not already using non-toxic / biodegradable toiletries and cleaning products consider changing to them. You can find a list of suppliers on the Green Tourism Board web page.
  • Do you encourage guests to reuse their towels and linen too? A card encouraging them to is well and good, but ensure that there is a towel rail in the bathroom, and all staff are aware of the programme. A proven way to increase reuse of towels is to use the concept of ‘social proof’. Social proof is a way of saying that people’s behaviour tends to be influenced by what others already do. To utilise this concept of social proof, provide an information card to guests telling them that many guests re-use their towels. 
  • Share your news: You might wish to say more about your energy saving actions in the in-room information, or in a small display near the reception / on your website.
  • Feedback: If you have a feedback form, you can ask guests if they have any other ideas for improving the energy and environmental performance of your B&B / Hotel/ guest house / self-catering let.
    • Gadgets! You can encourage guests to be more aware of energy in a few simple measures. For example, could you place a fun shower timer in the shower? if it’s there, guests may well try it.

Further information on communicating to guests:

You can find out more about sustainability messaging to guests in these web pages:

Further Information

Here you can find detailed information and resources on water efficiency.

WRAP (Waste and resources Action Programme) has a wealth of resources on their website: . Particularly relevant is this report.

Green Tourism awards: Although the Green Tourism Award is not suitable for all businesses, they do have a very useful eco-friendly product directory online

Considering purchasing new products? Look out for the following labels:

Check the European Water Label website -You can easily browse and compare products according to brand name and water efficiency.

The Waterwise Checkmark

Still got questions?

Head over to the forum to post your questions or maybe answer a question for someone else. Learning from each other is a great way to share very specific knowledge to your community.