Q: High fuel bills? A: Low energy homes

If you live in the UK then you can’t fail to notice the media clamour, and subsequent political posturing, over the ‘Big Six’ energy companies rising their prices this autumn.   Energy customers are crying out to the political system to do something about raising prices, and politicians are falling over themselves to oblige.

Homeowners and tenants repeatedly feel like they’re being unfairly charged for their energy use, with little that can be done to combat rising bills.  The message from the public and politicians seems to be: Make Our Energy Cheaper!  I would counter with: Use Less Energy!  But how realistic is that?

One example of how using less energy can be achievable, and which offers a view into the future of housing in the UK, are the eight ‘passive’ houses on Dormont Estate, about five miles southeast of Lockerbie (Scotland).  This experimental new development, which was finished in 2011, was built to provide cheap rented accommodation through two means: 1) affordable rent, since the average annual wage in mostly rural Dumfries & Galloway is £20,800 [1] (£5,000  less than the national average) with affordable properties to rent or buy difficult to come by (due to second home ownership, for example); and 2) avoiding fuel poverty since, like most of the UK, there is much old housing stock in D&G which is poorly insulated and massively fuel inefficient.

With this remit, my father, his architect David Major of White Hill Design Studio, and CCG Homes used a grant from the Scottish Government to design and build the eight semi-detached houses to the German Passivhaus (‘Passive House’) standard and rent them out at an affordable rate.

Passivhaus

Dormont Passive Houses – 2 bedroom

The essence of the standard is simple: build a house which is so well insulated that energy from sunlight and people inhabiting the house is all that is required to heat the entire house.  The house is effectively sealed when all the windows and external doors are closed to achieve as little airflow as possible: 0.6 m3 m-2 hr-1 @ 50 Pa, compared with the current building standard of 10 m3 m-2 hr-1.  Fresh air is drawn in and heated with expelled stale air using an electrically-powered mechanical heat recovery system.  Hot water is generated with solar panels, and the whole development is south facing for maximum solar gain.  And if it’s still not warm enough, then there is a small wood burning stove in each house to top-up the heat [UPDATE – see comments on use of the wood burner for heat].

Passivhaus

Dormont Passive Houses – 2 bedroom

A great demonstration of how well the system works was given in a recent BBC programme The Great Big Energy Saving Challenge – watch the clip, below.  Although there have been some teething problems, the residents love how warm and cheap the houses are to run.

Video link: http://www.bbc.co.uk/programmes/p01g4jxg

Passivhaus

Dormont Passive Houses – 3 bedroom

Given the experimental nature of these houses (there are only a small number of passive houses in the UK), four of the homes were selected for a more scientific study by Donald Shearer and Dr. Tim Sharpe from MEARU (Glasgow School of Art) of how well they perform, based on measured temperatures, internal CO2 concentrations, and energy consumption [2].

The results of the study are based only on a two week period in February/March 2013 of thirty houses in Scotland which have been build to a low energy standard, but with only five of these houses built to the Passivhaus standard.

I won’t discuss in detail all the results, but the summary would be:

  • Despite achieving the Passivhaus standard immediately after construction, the four houses at Dormont were measured at 2-3 m3 m-2 hr-1 , showing a deterioration of airtightness over the last couple of years
  • Mean and max temperatures exceed 21°C and 23°C, respectively, for living rooms and bedrooms in all of the properties (and around half of the others in the study)
  • However, despite such regular high temperatures, energy consumption is between 1 and 1.5 kWh/m2 [I suspect there’s a time unit missing…] for three of the four Dormont houses, compared with between 5 and 10 kWh/m2 for the other houses in the study.  The fourth house was rated at nearly 5 kWh/m2, apparently attributable to the constant (95%) use of the immersion heater for hot water, so this is essentially ‘user error’!
  • Internal mean CO2 levels are around 500-1000 ppm, indicative of air quality, which rises significantly at night in bedrooms with maximum levels of up to 5000 ppm in some houses, however the mechanical ventilation systems integral to the houses at Dormont ensure that air quality is better than would be expected of a ‘sealed’ house.

The scientific and anecdotal evidence so far shows that buildings of this standard are easily and cheaply heated.  The energy bills of the tenants in the Dormont houses have, of course, increased just like everyone else, but when you are spending hundreds of pounds on your fuel costs, instead of thousands, then that additional cost doesn’t seem so desperately unbearable.

Going back to my point about reducing energy, however: is it realistic?  Clearly not everyone has the luck to be renting a super-efficient home.  In fact, hardly anyone does!  Those on low incomes, or indeed those on good incomes but with other financial pressures, cannot simply afford on their own to adapt their homes to this kind of standard.  But small gains can be made, such as draft-proofing windows and doors, moving your TV away from the window, not making 1000 cups of tea every day, etc.  However, we still need a helping hand if we truly want to commit to reducing our energy consumption.

I don’t want to particularly make any more of a political comment on this blog, but I would view very dimly any attempt by the current (or future) governments to postpone, reduce or remove commitments to improving energy efficiency in our homes.  A recent UK Government report [3] highlights the need to keep on with our ‘green’ policies, and not cut back as the current Government seems pressed to do, either under public or industry pressure.  A quote from the report, to finish (my bold emphasis), highlights that any reduction in green policies now will likely lead to higher fuel bills in the future.  Short-term gain, long-term pain:

DECC has estimated that current energy and climate change policies added around £33 (5%) to a typical domestic gas bill in 2013 and £80 (14%) to an electricity bill. Their analysis across the full range of current and previous policies suggests that they have not changed gas bills but cut electricity bills by around 3% compared to what they would have been with no policies….Real increases in typical bills to 2020 are forecast to be 6% for both fuels. In 2020 the full range of policies are projected to cut typical gas bills by 1% and electricity bills by 11%.

References:

[1] Region’s wages lagging behind, 10th July 2013, Dumfries & Galloway Standardhttp://www.dailyrecord.co.uk/news/local-news/regions-wages-lagging-behind-2533746

[2] Shearer, D., Sharpe, T. (2013).  A comparative study of the monitored performance of low energy dwellings in Scotland.  Conference Proceedings, PLEA2013 – 29th Conference, Sustainable Architecture for a Renewable Future, Munich, Germany 10-12 September 2013.  Retrieved from: http://www.baufachinformation.de/buch/240027 (Paywalled)

[3] Bolton, Paul (6th November 2013).  Energy Prices.  House of Commons. Standard Note SN/SG/4153.  Retrieved from: www.parliament.uk/briefing-papers/sn04153.pdf‎

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2 thoughts on “Q: High fuel bills? A: Low energy homes

  1. Good article Kit!
    Coming from Germany I always wondered why the energy efficiency of new buildings here are is so low. My dad has a construction business as well and he builds wooden, ecological passive houses. They work very well and have a very good living climate inside!
    I think the UK government and politics really fail do do more. In Germany many counties regulations nowadays make you build passive houses if you want to build a new house and if there are public buildings redeveloped they have to be passive house standard as well! Generally they cost about 8% more than “normal” houses, and I think that is well worth it because you can safe a LOT of money on energy bills (and greenhouse gas emissions..).
    One of the problems is, at least from my experience, that many people in Scotland are not aware of what a passive house is or how much energy you could save. That and the fact that people don’t seem to mind that their windows are basically nothing more than see-through piece of paper makes it hard to convince politicians to start changing things…

    Cheers,

    joho

  2. 90% of the heat from the log stoves in the Dormont Passive Houses goes into hot water with only 10% available for space heating. The stoves are so efficient that, when they are on, you can put your hand on the casing.

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