19 Jul 2010

Why are we saving water?

Is it me or is there something fundamentally wrong about Part G and the water calculator? It troubles me. I think the introduction of the water calculator methodology is taking the building regs into areas where they really shouldn’t be venturing. And I think it’s all going to come unstuck.

For those readers who haven’t a clue what I am banging on about, you could do worse than read through some of the stuff I have already blogged about on this topic. In essence, the regs now require that when you submit plans for a new house, you have to show that your water-using appliances will notionally only consume 125litres of water per person per day. You do this via a little spreadsheet-type-thingy called the Water Calculator which ranks appliances such as showers, taps, toilets and washing machines and gives them all notional scores set out in litres/person/day.

You can see where they are coming from, and I understand how the Water Calculator came into being. They want us to use water wisely and not just pour it down the drains.

There are two very simple ways of achieving this goal, and one very complicated one. The simple ways are to 1) charge the right amount for the water and 2) insist that appliances sold should meet defined efficiency standards. The complicated way is what Part G is now insisting on. Which is to try and regulate the end user behaviour by making them purchase water efficient appliances when they are building a new house.

The problems with this approach are numerous. Firstly, it only applies to new homes. Thus regular power showers will still be available from stores, but you will only be able to buy them if you want to replace an existing bathroom. Can you imagine how infuriating that will be to people building a new home? Can you imagine going to buy a new TV and being told you can only have a plasma one if you live in an old house?

So what will happen? People will get their eco-shower heads passed by the building inspector, and then rip them out and put in the power showers they have by now started salivating about. Nothing illegal about this at all. It’s just what happens when you make unenforceable regulations like this.

Nowhere in this Calculator approach is there any recognition of whether a particular shower or tap or bath is any good. It’s all down to the flow rate, or the flush quantity. For instance, a 4lt toilet is only beneficial if it works on the first flush. If you have to flush two or three times every time you take a dump, you might just as well fix an 8lt loo. But the spreadsheet isn’t concerned with this at all.

Manufacturers can’t even produce “Part G compliant” gear, because Part G doesn’t set any limits for indivual appliances; it’s only concerned with this overall total of 125lts/person/day and it leaves the end users to decide how they will meet this target.

Part G has also got holes as big as a swimming pool. Literally. Swimming pools are exempt from the calculations. Far be it for me to turn class warrior, but somehow this little “oversight” does rather stick in the craw.

But there is something else that troubles me too. Whilst I am convinced by the arguments that we should be using less fossil fuel, I still have my doubts about whether water is quite the precious resource that we keep being told it is. Put another way, why are we being asked to make all these sacrifices?

Are we actually short of water? The situation varies enormously across the country. Not something Part G can take into account as it applies across England & Wales. Even in the dry and populous South East, we are rarely hit with water shortages. If there is an impending crisis, it is likely to be as much an infrastructure failure as anything. We could have invested in a national water grid, but instead have chosen to do things on a piecemeal basis.

The one thing which would make matters worse is a huge housebuilding programme in places like the Thames Estuary. Limiting water consumption in areas like this makes sense, but it could easily be done by local bye-laws. It doesn’t require national building regs to be changed.

What about the environmental impact of using water? Again, a very difficult thing to measure, because there are many impacts and they are not readily comparable. But an interesting blog piece over on oCo Carbon suggests that one major impact, the carbon intensity of unheated tap water, is quite small. It ranks at 0.59gmsCO2/lt. This means that the carbon intensity of the water piped into the home of the average 150litre/day person is just 32kg/annum, the equivalent of running a 6watt appliance throughout the year. It’s dwarfed by the energy used to heat much of this water — as much as 50% of what we consume via the mains is heated before it’s poured back down the drains.

Now there are good arguments to limit the flow of heated water in order to save energy, but this is not what Part G is all about. It’s explicitly trying to stop us using too much water, not trying to stop us using too much hot water. If hot water was the target, then there would be no need to include toilets in the Water Calculator.

To be fair, the topic of water consumption is more complicated than my brief summary suggests. We are also indirect consumers of water and almost everything we consume involves the use of water somewhere along the way, sometimes extraordinary amounts of the stuff. The same blog piece points to a report which suggests that our water footprint is 30 times larger than what we directly consume in our homes. It may well be, although just how you would go about measuring it is something I can’t begin to comprehend. But no way is Part G and its Water Calculator going to have any effect on this and it all makes a mockery of Part G’s attempts to limit the flow of our show heads.


  1. Dave HoworthJuly 19, 2010

    I couldn't agree more.

    Some parts of the planning rules and the building regs are arcane or bizarre. Some parts I'll try to steer away from and some I'll negotiate carefully, and some - bless'em - I'll embrace wholeheartedly.

    But Part G is the first place where I've come to the conclusion that my goal when I build a house will have to be to find ways to circumvent and abuse it as far as I can.

    Perhaps there's a business to be made hiring out compliant sanitary ware etc that's quick to fit and just as quick to remove!

  2. Mark,
    I am glad somweone has finally blogged about this. A lot of what has happened with building regs recently is bonkers but this tops the lot. You get the same issue with the Code. People are specifying fittings which are literally guaranteed to be ripped out. They are effectively unuseable. My suggestion to shower manufacturers is to fit some flow reguilator which can be removed after purchase. Or maybe they'd prefer selling one to the builder and one to the homeowner afterwards. (It is particularly nasty because the only people who will be stuck with these fittings will people renting privately and in social housing. Let's hope building control just ignore it.

    This comes on top of the new definition of zero carbon about to be produced which will only go to demonstrate that buildings can't realistically be zero carbon. There will be a masssive bureaucracy working out what is and isn't acceptable as an allowable solution and how to calculate what is required.

    Then there are the FITs or 'how to get poor people to pay rich people's bills and pay companies to gloat about how they are reducing CO2 emissions'.

    My grandmother recently used the Warmfront scheme to install gas central heating in her old single glazed home. Once the survey had been performed they specified all the radiators to be on the internal walls. I rang up DECC to explain their mistake and how this was against every bit of guidance out there, (HVCA, BSRIA, CIBSE) for providing comfort and saving energy and was told I was wrong and they wouldn't change it anyway.

    The point of my rant is that all the schemes have been signed off by the civil service. In each case someone must have realised the lunacy but just carried on, maybe to curry fabour internally. Is there a group you can join to act as concerned professionals in the industry to act as a counterweight?

    Please God, let someone see sense before we have the Renewable Heat Incentive.

  3. AnonymousJuly 20, 2010

    "Perhaps there's a business to be made hiring out compliant sanitary ware etc that's quick to fit and just as quick to remove!"

    Plastic disposable taps!

  4. AnonymousJuly 20, 2010

    yep. I thought that - hiring out toilet ware like you can hire out furniture for tarting up a house before sale.

  5. This is clearly the type of thing people will try to get round all the time, stupid idea.

  6. Another idiosyncrasy to do with water is that of water companies banning hose pipes during a drought even though most of water is used internally in toilets etc rather than watering the garden or cleaning the car.