By Paul Chatwin

I have six years of monthly gas, electric and water home meter readings. I read the meters religiously each month, log them on a spreadsheet, and then do very little with the data. I know for 2016 my consumption was circa 14,000kWh gas and circa 2,500 kWh of electricity. This converts to 3,700 kgCO2e. But is this any good? I didn’t really know the answer. That is until Module 2 of the Cundall Diploma, which is built around 13 modules over a two-year programme.

Module 2 required either a home or work place energy audit together with a plan for improvement. At last I thought, I can use my data and see what can be done. My wife and I have two young children living in a four-bed mid-terrace house built in 1999. We switch lights off, although I am reliably informed the kids won’t do this when they are teenagers, and our main house improvements have been replacing the doors and windows with modern double glazing. We have also had free cavity blown insulation installed, added more loft insulation, improved boiler controls (however this can lead to more comfort and not necessarily less energy) and of course the usual LED lamp replacements. Most of our lights are efficient with LED’s apart from the ‘expensive’ one my wife won’t allow me to replace in the living room! It has twelve 25 Watt halogen bulbs! It does not take a rocket scientist to work out that this is excessive. At first I partially filled the fitting with lamps, more recently I used LED replacements but only to six LED and two halogens as the light flickers (transformer issue) with any further reductions. The saving grace is that the light from the TV, the fish tank and a 4 Watt table lamp is used most evenings.

Back to the diploma, one of the requirements was to compare my energy with my colleagues. I emailed everyone in the Birmingham office asking for similar data to provoke chats about lifestyle and occupation patterns etc. My research resulted in twelve sets of 2016 gas and electric bill data. So, how good was my consumption in comparison? Being competitive, I had high expectations. We ranked 5th lowest, I was ok with this. But the lower consumers included a modern 2-bed house with 2 professionals, another was a similar house to mine but with one young professional. So not comparable. If you broke the consumption down to carbon per person we came first i.e. lowest. This made me happy!

Compared to U-switch (a UK based free and impartial energy provider comparison website) our consumption was close to medium being only 1% more (when considering carbon emissions kgCO2e. Medium category being a 3-bed house, 3-4 people, small family, clothes washing 3/week, heating and appliances used all day). Compared to British Gas previous 3 months and post code we were 12% lower than ‘Average’.

This is all good, so now I knew we were efficient in our usage compared to colleagues’ data and compared well against benchmarks, but I also knew through my research that I was 27% greater than passivHaus energy requirements. Could I get near to passivHaus? That, in my view, would be worth writing about.

To achieve this goal, I would need to cut emissions by a quarter, circa 1,000 kgCO2e. As part of the Module 2 I identified five initiatives that totalled a potential saving of 900 kgCO2e. The first initiative was aimed to reduce unwanted heat loss through draught strip replacement arounds doors and replacing extract fans in bathrooms with less-leaky ones (130 kgCO2e potential saving). The second initiative was to replace the boiler, this I estimated could save 450 kgCO2e. The third initiative was replacing the hot water storage cylinder to potentially save 110 kgCO2e, then I looked at replacing the few remaining non-LED lights to LED which would save 33 kgCO2e and lastly, but importantly, changing our behaviours could easily save 180 kgCO2e.

The five initiatives were identified in January 2017 (five months ago). The initiative with the greatest opportunity for reduction was changing the boiler we did this at the start of April and with religious monitoring of the gas meter (almost daily) we are set to make almost a 25-30% reduction in gas consumption. Even with a 25% reduction this would lead to 625 kgCO2e annual carbon savings (approximately £100 a year).

I may blog again later this year to see how much lower we can go, whilst remaining comfortable. Some of our gas savings are just down to changing behaviour, we simply don’t heat the house as much as we used to.

Join the conversation! 2 Comments

  1. Hi Paul – I am curious as to how low you managed to go over the last 18 months. But in particular, did you get around to changing your boiler? I must confess it is something on my own to-do list. Any guidance or insight would be most appreciated. Cheers, Kate


    • Hi Kate,
      I replaced the boiler March/April 2017. e are realising 25-30% reduction in gas. So really pleased. When choosing a boiler we considered a combi. Combi benefits was more space (no tank in airing cupboard). But we needed to increase gas pipe and no back-up for hot water if boiler failed in the future (tank has electric elements so hot water is always available). So we stayed with traditional. I tried to be clever and get a boiler with an outdoor temp sensor for direct weather compensation (more condensing = increased efficiency) – but we had to remove the feature as the hot water was not getting up to temperature, this is a limitation on controls. Good luck.



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Paul Chatwin, Sustainable Cundall, Working at Cundall


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