By Libby, Mar 25 2019 12:00PM
A Story of Insulating our homes against the Cold using Less Fossil Fuel, and ending up In Credit
On a very cold and damp morning just before Christmas , an intrepid gang set off into the wilds of the Suffolk countryside to experience at first-hand the reality of spending a few hours in a house which effectively does not pay for electricity, and would not be turning on its central heating for our benefit!
Our group was from Greener Rendlesham with a couple from Greener Waldringfield, and we all met
up shivering that morning in the corner of a small field adjoining the property.
As we made our way towards the house, we had a chance to admire the small wood, and the very large wood-piles, and also many fruit bushes and wildlife pond.
Our hosts, John and Maureen Midwinter, made us very welcome. Straightaway, we all felt warm and cosy although we could see no sign of a fire or source of heat in the room.
We were made comfortable, while John gave us a slideshow and a short and fascinating talk - He told the story of how he and his wife had come to settle in a house which had originated as a row of four cottages built in 1873, and how he had improved the current house to match the highest of modern standards for
self-sufficiency in energy needs.
At first, back in 1980, John could see no great attraction in this damp, cold and draughty property - but his wife had fallen in love with it - so there was no going back!
The original conversion in 1970 had created one house from the four cottages, with some underfloor heating and half an inch of loft insulation! The heat loss was immense - needing 1200 watts of power to increase the temperature inside the house by only one degree . It was impossible to heat it properly, as so much heat was lost through roof, windows and walls. John quickly laid 10 inches of loft insulation, and installed double glazing - Job done? No, the walls remained a problem - those 10 inch-thick solid brick walls were keeping the place chilly.
The solution? After much research, and a lucky break, John made the decision in 2011 to invest in a particular solid wall insulation cladding. A company from Norfolk came and installed the large German-made cladding blocks over the exterior, and it was soon in place, covering all the walls, and shaped around the window openings and gutters.....How did it look? .....at first, John’s wife thought it looked “bonkers” but once it was rendered and returned to its familiar Suffolk-pink colour ......well, these days no-one notices that the house has had a warm overcoat applied, it looks so natural. Maureen was very happy.
And John was happy too. Once the cladding was in place the house began to warm up.
Over the space of 10 days, slowly every room crept up to the same temperature. There had been an 86% reduction in heat loss through the walls - they could really feel it, it was quite dramatic . Now all those thick brick walls are acting as a thermal heat store, so even if there was no heating inside the house, it would
take a whole week for it to go cold. The technical term - it has a very ‘long thermal time constant.’
And the other main source of heating? A simple 9Kw log-burner from a local supplier, which sits in the centre of the building, and serves to warm both upstairs and downstairs. Fortunately, Maureen had organised the planting of a good many trees on their piece of land some years earlier, and now there is a nice store of timber drying off in the various woodpiles which we had seen on our arrival. John estimates that this supplies about 60% of their current home heating needs, and it is lit in the evenings whenever the weather is cold. In fact the logburner was lit for our visit, so we could feel how it was used to boost the
Most of domestic energy use is for heating, so that was taken care of .
Next in terms of consumption are electrical lighting and then electric appliances such as the kettle, cooker and laundry machines. To bring down their electricity costs, in 2011 John had 16 Solar PV collectors installed - 8 panels on the east and 8 on the west-facing roofs. On average, these panels generate 3,000 Kw hours of electricity per annum - the final outcome is that the electricity company pays the Midwinters more than they pay the company, the balance roughly covering the cost of heating oil.
In 2006, a solar hot water panel was installed, and this supplies about 60% of the hot water averaged over the year. There is also an oil burner which provides top-up heating when required, although very little oil is used.
Calculating the cost of the improvements against how much money is saved (or ROI - Return On Investment) - the result is an average ROI of around 14% per annum. I’m sure we’d all like to make 14% interest on our bank savings!
But perhaps the most encouraging figure for the folk from Greener Rendlesham and
Waldringfield is this:
THE OVERALL IMPACT HAS BEEN AN 80% REDUCTION IN FOSSIL FUEL USE.
John kindly answered our many detailed questions on the improvements - their cost, how to measure the efficiency, what alternatives might be available, how our own situations compared, and so on - and we all appreciated his kind patience and quiet enthusiasm. An expert, and a delightful speaker, we thank him for giving us inspiration to follow in his footsteps. And thanks went also to Maureen for the delicious refreshments, which kept us going on our memorable visit !
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