Why We Need Efficient Houses
Rod Holt has volunteered with Otley 2030 for the past three years. He's expert on energy and retrofit, having spent the past decade experimenting on ways to make his own house more energy-efficient. Here he shares his thoughts on energy efficient houses in the UK...
Bottom of the Class
In our earlier blog about The Gas Price Hike, was the sobering revelation that British houses are among the worst in Europe in terms of energy efficiency - this costs British people, and the local and national economy dearly.
There are about 28 million homes in the UK, and the average annual fuel bill is already very nearly £2,000, with worse to come. Some wonderful things could be done with £56 billion per year, but instead it disappears into the bulging coffers of the oil and gas companies who use it to buy influence and fund disinformation about the climate changes that their products cause, or into Vladimir Putin’s war chest to buy shells, bombs and missiles to kill innocent people.
In spite of the huge national fuel bill and the personal pain associated with trying to pay it, many British houses fail to provide decent living conditions for their occupants, and many people grow up and grow old in homes that are too cold in winter, too hot in summer, stuffy in settled weather and draughty in a gale. They are often damp, sometimes mouldy and always environmentally ruinous.
Yet we believe we are civilised people who belong to one of the world’s most technologically advanced nations, and that British life and values are an admirable example for the rest of the world to follow. Because most of us have never experienced anything better, we do not expect anything better, and those who profit so greatly from selling us the oil and gas, to which they keep us addicted with their deceptions and political meddling, exploit our ignorance gratefully.
There are however one or two amongst us who have taken the trouble to investigate and understand this matter, and a few fortunate people are able to have houses built for them as though the wellbeing of people and the stability of the atmosphere were more important issues than the personal fortunes of the directors of firms which build our crap houses and the companies who supply the ludicrous amounts of damaging fuel needed to heat them.
There are also a few enthusiasts who have acquired the knowledge and skills needed to make our existing homes, (whatever their degree of antiquity) fit for civilised living in times of rocketing fuel costs and atmospheric carbon dioxide levels.
Although long considered eccentric, these people are now untroubled by rising fuel bills, and their example points to an escape route, indeed the only practical exit, from our current distress.
Surely our houses aren’t that bad…?
A figure of merit for houses is the Specific Energy Requirement, which simply indicates how many units (kilowatt-hours) of oil, gas or electricity are needed each year to keep each square metre of living space comfortable. A typical house could have 100 square metres of floors. Most of us would recognise the top five categories in the table above, and could well live in one of them, which, if over a 100m floor area, would consume between 9,000 and 35,000 kWh of fuel each year. This is now at a cost many of us can no longer afford, with correspondingly huge CO2 emissions.
At the bottom of the chart is Passivhaus, a design concept originated in 1988 by the Swede Bo Adamson and the German Wolfgang Feist, and further developed since then. Houses built according to Passivhaus principles waste very little energy and offer their occupants healthy and comfortable living conditions, regardless of the weather outside. Other systems with different names offer similar advantages using slightly different methods. They generally cost a little more to build than conventional houses but offer permanently low fuel cost, with additional savings due to the improved health and wellbeing of their occupants. If the little energy required each year is generated by a local solar PV system, the fuel costs could even be zero!
Next up is Enerphit, which is a system where Passivhaus principles are applied when renovating old houses to improve comfort and efficiency - a process known as retrofitting. Most existing houses incorporate features which make the very high energy savings of Passivhaus difficult to achieve, but excellent results can nonetheless be had, with 80%+ energy savings in many cases.
It was once considered too expensive to make these improvements, but recent developments show clearly that it is too expensive not to.
So how’s it done?
Ventilation controlled by the occupants, not the weather.
Heat recovery, so warmth isn’t lost along with extracted stale air.
Triple glazing which offers comfort from the outset and is cheaper after a few years too.
Energy-efficient doors which do more than just blocking a hole in the wall.
Floors carefully designed to reduce heat loss and keep feet warm.
Walls carefully designed to reduce heat loss and eliminate condensation.
Roofs carefully designed to reduce heat loss and maintain ideal internal surface temperature.
Design and orientation to increase natural light and winter solar gain and to reduce overheating.
Attention to detail to eliminate air leaks and thermal weak points in the structure.
Heat recovery from waste warm water.
Efficient electric heat-pump based heating / cooling / hot water systems. No gas.
Smart systems to use and trade electricity advantageously.
We’ll have a more detailed look at all of the above in following posts in the near future.
If you’re in need of specific advice now, please email hello@otley2030.com