I’ve been writing water saving suggestions into my architectural urban regeneration and domestic projects for years and well before the building regulations AD Part G 2016. It’s good practice to consider water saving measures, even though most developers /small builders don’t think it’s that important.  We have to think about it of course, with new housing but domestic retrofit projects are exempt for compliance with Part G.


Clients seem to appreciate the explanations for the long term benefits for water saving and therefore ‘running cost’. When it’s considered alongside replacing old fittings or just upgrading taps or showers, it’s a good payback. Water savings are typically ignored when it comes to trying to put most of the effort into energy saving as the ‘forgotten utility’.


The less water we consume, the more CO2 we save as the water companies don’t have to spend energy purifying it and the addition of chemical use, only for us to flush it away down the drain. According to the Energy Saving Trust we flush around 30% of our daily water use down the toilet. That’s domestically the equivalent of 4.5m3/month or 54m3 per year. In Yorkshire the cost is around £100 wasted. The standing charge is £68/yr for water and sewerage but there doesn’t appear to be any incentive by the water companies to provide subsidised water saving measures or clients installing water harvesting measures, by offering a reduction to the annual bill for doing so. No ‘brownie points’ here, perhaps just the indifference of shareholders?


In addition, the Government calculates 1m3 mains water has 0.344kg Co2e *

The average household is allowed 125litres/person/day  (Code Level 0) under building regulations Part G Approved Document and is still way off where we should be targeting.

Part G is not mandatory for existing homes but surely it should be and incorporated into all refurbishment and upgrade projects as good practice?

A Code Level 5-6 Ecohome, being sensible with water should use around >85 litres/per/person/day mains water. This produces an actual use per month (for a family of 4) of around 15m3 or 180m3 /year

Freeflush Ltd, a NW based company specialising in water saving, harvesting cutting carbon and water neutrality estimate the average household use is around 163m3/yr

Either way, that’s between 4.5-5 tonnes embodied carbon Co2e and annually about 56-60 tonnes Co2e to generate clean water.


In a time where standing charges for utilities are being increased because they can be increased and water production costs are predicted to rise significantly by 2023** its worth investing in water saving measures now.

Is it any coincidence that some of the current worst problems we face is in the London region where Thames Water charges the least amount per year than other regions. Combine this with shortsightedness to allocate areas to build more reservoirs for a growing population (the last one was Carsington Water, Derbyshire, 1992) and a few others in the Southern England, due on line from 2029, we have an imminent and expensive problem upon us.

Now is the time to be sensible and reduce our water use.


*(e= embodied carbon Ref> www.twinfm.com).

** Yorkshire water website

The Carbon Cost of Water Consumption – Richard Dawson, UK