living: 30 years from now

Our pick of the best reads:


Jeff Rubin "Why your world is about to get a whole lot smaller"


 

Greg Craven "What's the worst that could happen?"


Lester Brown "Plan B 3.0"


Shaun Chamberlin "Transition Timeline"


Andrew Simms & David Boyle "The New Economics"


Anthony Giddens "The Politics of Climate Change"


Tamzin Pinkerton & Rob Hopkins "Local Food"


Clive Hamilton "Growth Fetish"


Richard Heinberg "Peak Everything"


Richard Heinberg "Oil Depletion Protocol"


"The Green Building Bible" vol 1


Mark Lynas "Six Degrees"


Donella Meadows, Jorgen Randers Dennis Meadow "Limits to Growth"


Aubrey Meyer "Contract & Converge"


Alexis Rowell "Communities, Councils & A Low-Carbon Future"

 


 

Proud Co-Founder of Transition Town High Wycombe

 

Proud Member of the Low Carbon Chilterns Cooperative

LCCC

 

Proud owner & retrofitter of Superhome 59

Superhome 59

 

This website proud host of the High Wycombe Local Food Guide

Local Food

 

See what's going on with our Superhome 59 YouTube Channel

Superhome 59 YouTube Channel

Making a Superhome - living 30 years from now

 

Welcome to Superhome59 - a five bedroom family home in Buckinghamshire, UK. 80% of all the homes we will be living in by 2050 are already standing today. As much as we would have loved to have moved into a shiny new passivhaus there were none available - so we went with what we had. The objectives of this retrofit were multiple: firstly, massively reduce our carbon footprint; secondly, reduce the amount of space and hot water heating required; thirdly, reduce the amount of electricity we needed; fourthly, provide space to grow our own food; finally, reduce our water consumption. This was less of a project and more a program of works designed to modernise this old home as subtley as possible. Not so much an "eco-refit", more a modernisation. We took a typical old home and future-proofed it. Come on in and see what we did... 

Visit this Superhome in March 2013!!!!!

Visit the blog

March 2013 Open Days announced: come see us on Saturday 23rd & Sunday 24th March 2013. You can book your place by going to: www.superhomes.org.uk/59. Max of five people per tour. Tours last 50 minutes. You now also have the chance to see Superhome 113 via www.superhome113.info some 2 miles south uf Superhome59. Contact us for details.

How to find us (with bus route info):

View Larger Map

Post-Carbon Home One

This is not our first attempt to retrofit a home. Prior to the commencement of the current phase of work on Post Carbon Homes there was an earlier experiment on a home some three miles to the south of our new location in High Wycombe, Buckinghamshire, UK. We too everything we learnt onto the current Post-Carbon Home when we moved location in May 2008. If you would like to learn more about this home please click here.

Where we were in May 2008

The property was purchased in 2008 and we moved in in May of that year. The house is quite average in many respects but we chose it for a couple of important features:

 

  • A large Double Garage

  • A large South-Facing Roof

 

This was one home that had considerable room for improvement. Since it was built in the mid-1980's the previous occupants had performed some cosmetic modernisation on the interior but had, otherwise, made few practical improvements. When we moved in we found the following horrors:

 

  • No Cavity Wall insulation

  • No Water Pipe insulation

  • No Domestic Hot Water Cylinder insulation

  • Less than 100mm of Mineral Wool loft insulation

  • No Insulation Jackets around either Hot Water or Heating Header Tanks in Attic

  • Some very bad DIY plumbing

  • The original 1980's Gas Boiler

  • Rudimentary Heating controls/timer

  • Built-in Kitchen appliances of unknown efficiency rating

  • Gas Fire in Lounge to Open Chimney

 

To the previous owner's credit they had replaced the original single-glazed window units with White PVC Double Glazing - but that was about it. So we inheritted a house in fairly "average" condition for its age. It reflected most people's priorities over the last thirty years. Energy was cheap and Climate Change was just a theory. (As an example the ceilings had been punctured to install recessed ceiling lights. A very fashionable idea at one time but a nightmare for anyone trying to make a house air-tight to modern building standards.) We obviously had a lot of work to do. It was an ideal opportunity to demonstrate some best practice for the modern household and the informed DIYer.

 

The biggest challenge for us will be engaging a sympathetic Local Planning Authority. The House is in a Conservation Area and Smoke Control Zone. Although this will not impact most of the basic changes to the internal systems, it would mean Planning Permission (&/or careful product selection) for such work as:

 

  • New Conservatory

  • Bio-Mass Boiler

  • Wood-Burning Lounge Stove

  • Tree Removal/Planting

  • Photovoltaics

  • Solar Thermal Panels

 

Before we bought the property we had already made an informal approach to the local Planning Authority to ascertain their attitudes to Solar Panels. Good news - they were sympathetic and stated that they were unlikely to raise any objection. However later enquiries about lists of locally approved Bio-Mass Boilers with the "Air Quality" Officer met with a less-than-useful response. Clearly we were in for interesting times. On the flip side we did have an interesting advantage - as the property was of brick & flint construction the walls were several cm thicker than other houses of that era.

Let's tour the building in its "moved in" state:

 

The Attic: It is enough to make you want to run away screaming. What you see is what you get. Less than 100mm of Mineral Wool Insulation between the joists. The entire area was lit by one 40w tungsten filament light bulb. The ceiling has been punctured in no less that seven locations as the traditional ceiling roses had been replaced by recessed ceiling lights. The recessed lights are not that useful in distributing the light around and make it a little challenging getting CFL's that fit the recess. What is more the ceiling in no longer air-tight. Air can leak directly through the light fittings and into the attic above. You will also see above the Hot Water and Heating Header Tanks. They were not insulated - well, not properly. The 50 gallon tank actually had some mineral wool just floating on the top of the water surface.  Oh yes, and we are not counting the seven Bees Nests under the rafters.

The Heating & Hot Water system: the Boiler belonged in a museum. Have a look at those heating controls in the second photo. The previous owners had had them just switched ON all the time. No wonder really. Most of the heat was lost on the way from Boiler to Hot Water Tanks through uninsulated Pipes running the length of the Attic space. On the right we see the Domestic Hot Water Cylinder. Yes it has rigid foam layer of insulation. But we found out the reason why. This has been replaced in 2003 for reasons unknown. Not a single pipe in this Airing Cupboard had any Insulation on it. The Cupboard remained a good way of cooking your laundry not airing it.

Whilst we are on the topic of heating controls - here is the Thermostat. Yes it is ancient but this is probably the least of our problems. Now lets turn our attention to all those Tungsten Filament Light Bulb Spots. There were fifteen "R63" spots and nine "R80" spots. Some didn't work but that was OK because the previous occupants had left a large bag of spares in the Garage. Obviously they had needed them! Within our first two weeks in the house two more bulbs failed. That is one a week. Talk about throwing good money after bad. We did find one energy saving lightbulb at the house - it was fitted inside the outside light next to the front door. Maybe if the money spent fitting recessed lights had been spent on CFL's the previous owners may have saved themselves some money. OK - enough bewilderment. Let's take control....

Resources

 

 

Where we are today

Before...

After...

 

What was done, what it cost and when we did it

ItemDateCostTypeComment
Double Glazingn/anoneSaving heatPre-installed. Probably the only eco-beneficial items the house had already!
Energy saving lightbulbsMay 2008£400Saving electricitySpotlight-type from Lightbulbs Direct
Pipe InsulationJune 2008£39Saving heatFrom a DIY store - fitted ourselves
Attic LightingJune 2008£55Project overheadNot a true eco-feature but necessary in order to insulate the attic ourselves
Loft Tank insulationJune 2008£37Saving heatFitted ourselves
New Loft HatchJune 2008£63Saving heatFitted ourselves
Sheep's wool loft insulation

June through October 2008

£999Saving heatWe added 200mm (2 layers of 100mm) on top of existing mineral wool. Purchased about 100m2 of sheeps wool (100mm deep) which cost us £999.
Attic flooringJune through October 2008£618Project overheadAn additional £618 was required for tools, wood and boarding gave us the storage space and access for future solar panel & boiler work via attic.
New kitchen door to garageJuly 2008£650Saving heatOld wooden door replaced with UPVc equivalent.
New door between garage and gardenJuly 2008£650Project overheadOld wooden door replaced with UPVc equivalent.
Garage DoorJuly 2008£1905Project overheadRollover Garage Door fitted by SWR. Not an essential eco-item but replaced the broken original. New roll-up door has a foam interior sandwiched between aluminium and plastic exterior walls. Helps keep the warmth inside the fabric of the building as the boiler is in the garage. It works too. High embodied energy but gave us good security.
New Gas Boiler, TRV's & controllerAugust 2008£2480Saving heatFitted by a local plumber. This boiler is now only a backup for the wood-pellet boiler
Chimney BalloonAugust 2008£30Saving heatFitted ourselves
Solar powered security lightsOctober 2008£122Saving electricityFitted ourselves but a big waste of money - later replaced by mains-powered versions that were much better
New CurtainsOctober 2008£240Saving heatThick lined curtains made to measure
Draught proofing & miscellanious insulationOctober 2008£80Saving heatFitted ourselves
Energy saving security lightNovember 2008£23Saving electricityFitted ourselves
Radiator FoilNovember 2008£65Saving heatFitted ourselves. We overspent on this due to an attempt to use double-sided sticky tape rather than wallpaper paste.
Energy saving security lightDecember 2008£99Saving electricityFitted ourselves
Cavity Wall InsulationDecember 2008£219Saving heatInserted by Mark Group
Wood Burner Dovre 250April 2009£2720Saving carbon - heatFitted by local company Nature's Warmth
A++ fridge/freezerJune 2009£420Saving electricityFitted ourselves. Replaced built-in units
Water butts and fittingsAugust 2009£70Saving waterFitted ourselves
Kitchen LED lightsAugust 2009£250 approxSaving electricityFitted by local electrician (ceiling units) & ourselves (undercupboard units). Supplied by Wattlite & Lightbulbs Direct.
Biomass Boiler KWB Easy Fire for Wood PelletsSeptember 2009£15590Saving carbon - heatFitted by Green Systems UK Ltd. Cost was £15,590 - £1500 Low Carbon Building Program Grant = £14,090
Water SoftenerSeptember 2009£1320Project overheadNot essential but we live in a hard water area
Barilla Solar Thermal hot water system & tankApril 2010£3750Saving carbon - heatFitted by British Eco - £1000 Low Carbon Building Program Grant = £2750
Photovoltaics 2.96kWp Mitsubishi panels & new consumer unitApril 2010£13500Saving carbon - electricityFitted by British Eco. New Consumer Unit fitted by local electrician.
Removal of trees from rear gardenJune 2010£855Making growing spaceLocal tree surgeon. These were mostly 18ft leylandiis that screened the home from the south blocking out the sun all year round. The house is far warmer in winter now. Replaced with fruit trees that will not shade the house even when fully mature and lose their leaves in Autumn.
Replace plumbing & toilets with lo-flush & lo-use optionsAugust 2010£800Saving waterFitted by local plumbers
Replace all radiatorsSeptember 2010£1450Project overheadFitted by a local plumber. The originals had all rusted through so we opted for slightly larger units.
Fruit TreesDecember 2010£152Making growing spacePlanted ourselves. Replaced the leylandii removed earlier.

 

GROSS TOTAL

£49,000

Total ignores LCBP grant funding that no longer exists. Note that the costs above exclude a lot of incidental expenses such as tools and materials.

 

Cost Breakdown

 

The total project cost looks quite horrendous but matters are not as simple as they first appear. The above list actually excludes things such as a new fitted kitchen and security system because they had no bearing on the nature of the 'eco-retrofit'. This means they didn't contribute materially in either saving water, energy or carbon nor did they increase our capacity to grow our own food. A more accurate breakdown is thus (figures are now net of LCBP grants):

 

Type of expenditureAmount spent overall
Saving heat (both space heating and water heating)£4902
Saving electricity£1314
Project overhead (non-essential associated costs)£5998
Saving water£870
Saving carbon - heat (doesn't reduce usage)£19560
Saving carbon - electricity (doesn't reduce usage)£13500
Making growing space for food£1007
TOTAL£47,151 net of grants

 

Since the project kicked off on the day we moved into the house we had no baseline. So we asked our friends at the Superhomes charity to supply us with starting figures used in their own assessment. (Our thanks to Gordon Glass, John Doggart and Richard Macphail for this.) They supplied figures for our home using the NHERS rating system that was tested by BRE. (It should have a 95% accuracy. NHER covers more energy use than does the current SAP assessment.) According to this measurement Superhome 59 should use 38,322kWh (“units”) of energy per year broken down into 34,231 for Gas and 4,101kWh for Electric.

 

We ran these numbers through our current Gas and Electric bills from NPower and calculated that this should be costing us £1,827 per year. The average UK household bill is £1,334. Today our gas usage is zero because we heat are home by wood. Electrical usage is 2,940kWh per year which is a 28% decrease. However we generate about 2,800kWh per year so are, effectively 95% self sufficient - unfortunately the sun goes away at night leading us to import energy. The billed import is 1,860kWh per year. Thus the bottomline electricity cost is £280 a year.

 

But what about all that wood fuel? We use about 4,515kg of wood pellets per year which equates 20,600kWh of space and water heating. That is a 40% saving on heating, but wood isn’t free. It costs about £0.25p/kg (pellets) which is about £1,100 a year. Add in the cost of electricity imports, logs for the wood burning stove in the lounge, maintenance & cleaning then the total cost to heat and power Superhome 59 is NOW £1,780 a year.

 

Only a saving of £80 a year? But still this is not the whole picture. That number is distorted because we used a renewable heat solution. It isn’t cheap. There is no current Government support mechanism for domestic renewable heat but this is slated to arrive in 2013. Until then there is one other significant support mechanism we haven’t mentioned yet: the Feed In Tariff. We get paid for the solar electricity we produce and we get paid well; about £1,600 per year in total (including payments for exporting electricity to the grid). This is tax free and increases every year with inflation.

 

So the total NET payment every year to heat and light our home is only £180. So we are saving £1,650 every year. Aha (I hear you ask) but what did it all cost? The total project cost was a startling £49,000 of which £4000 was not related to energy (for example: saving water, growing our own food, providing loft storage, and so on). Even at £45k that is a significant outlay by anyone’s standards. Most people will never earn that amount of money in any year, most will never buy a car for that amount, most could only dream of what that sort of money could yield in terms of luxury holidays. But, of course, you can borrow that money against your mortgage, if so lucky, to invest in your home. So the real question is: what’s the payback? Or, to put it another way: why not just invest that money somewhere else?

 

Now the maths could get complicated depending upon the discount rate you apply and assumptions about fossil fuel prices. But if we strip away the complexity and just use today’s prices then we get a payback of around 27 years - or about the length of a mortgage. To put it another way the return on investment is about 3.7% pa. (We didn’t compound the interest because you will need that to pay your bloated gas & electric bills.)

 

So what is the opportunity cost? You could have put the money in the bank. If you reckon the economy will grow at an average of 3% pa for the next 30 years then it MIGHT still be worth it. Of course there are other investment packages out there depending upon the level of risk you wish to take. In our case investing in our home was a zero risk strategy hence we should only use the lowest estimate. Of course this slightly misses the point.

 

Even if you had stuck the money in the bank mostly every penny of interest you earn would have gone on your gas and electric bill. So you are just standing still. Your capital may be more liquid than ours but our home is still our home. We get somewhere to live that is warm and comfortable. You still have to live in your cold and draughty house. Which brings us to the next point: carbon.

 

It is fun to figure out whether such an investment is worth it in terms of Carbon Dioxide saved. Europe has a Carbon Trading Market known as the EU ETS. In November 2012 one tonne of CO2 trades at just £6.58. So our £45k would have bought 6,838 tonnes of CO2. If I take the payback period of 27 years then in that period Superhome 59 saved just 211 tonnes of CO2. Putting it another way: it was 32 times more expensive to save carbon via a home retrofit than simply retiring carbon credits on the free market. My 211 tonnes earns me just £1,388 at today’s ETS price.

 

The bottomline is this: we generate 95% of our own electricity, cut our electric bill by 28% and our heating bill by 40%. However the sledgehammer we used proved to be so expensive that it only becomes worth it because of the Feed In Tariff. Even then the total project payback is quite low and only slightly better than leaving your money in the bank. Then you have to factor in the cost of replacing the renewable energy devices. The photovoltaics may well last 40 or 50 years but the electronic box of tricks that connects it to the grid will need replacing within 10 to 20 years.

 

Then there is that biomass boiler. It might last no more that 15 to 20 years. If you replace a gas boiler it might set you back £1,800 whilst the wood pellet boiler might cost £9,000. There is nothing clear cut about this decision. What you get is satisfaction. It isn’t about being smug. It is about security. Whilst everyone else’s bills went up 7% in 2012 ours went up by 1.3%. We have disconnected ourselves for the ugly death spiral of fossil fuels.

 

If we knew this would it have changed anything? To that the answer is truly “no”. Definitely not. What if we frittered that money away on holidays and fast cars? After 27 years we would have no cars, no holidays and we would STILL be paying through the nose to heat and light our home. So it was a wise investment because in year 28 it is still costing us less. Maybe not that much less – the Feed In Tariff ends after 25 years – but this home will probably stand for a hundred years or more with its carbon footprint 90% lower than similar homes.

 

Earlier we mentioned the FiT ends after 25 years and we didn’t really account for this in the payback period of 27 years. In reality we have two years without that £1600 FiT payment which means £3200. Without FiT the payback pa was only £80. This would leave us another 40 years to pay back totalling 67 years. Obviously this is so far out in the future that it is really hard to tell what will happen. This certainly reduces the APR to 1.5% hence lower than “normal” economic growth and investment returns.

 

The other factor that wasn’t fully disclosed above was the heat input from the lounge wood burning stove. This was fully costed but wasn’t accounted for in the 40% heat load reduction. We use roughly 3m3 of logs pa. Below we have looked up the kWh by volume of wood and have corrected that saving figure but it won’t change the payback.

 

There is a third element of saving that wasn't included and that was water usage. We are on a meter and pay only £5 a month for water as we are low users. However we had already discounted the costs of water saving from the total capital costs, so this element was excluded.

 

The conclusion remains thus: the project had good payback on all elements apart from the Renewable Heat element: the biomass boiler. That gave us our biggest “carbon hit” but it made the carbon savings very expensive. Once these high costs are pro rata’d across the entire project it makes it look very unnattractive. The Renewable Heat Incentive for Domestic UK Residences arrives (after a long wait) in 2013. It will probably be 2014 before we really know its true contribution. All things being equal the RHI should restore the payback for the project and make the result worthwhile.

 

It does go to prove that the three key elements to de-carbonising UK housing stock will be the three key UK Government Policies: FiT, the RHI and the Green Deal. (The Green Deal was not relevant for this project because it didn’t exist and we funded the improvements ourself – this was probably a good things as we avoided interest charges that way.) Most homes will need one or more of these options. To go the “whole-hog” you will need all three and plenty of cash upfront. Currently not for the faint-hearted.

 

So that's the philosophical argument based upon the entire cost of the project. What happens if we break down the paybacks into separate chunks? So we split the project into three technology types:

  1. Insulation/solar thermal & the savings in heating/hot water

  2. Electricity and the savings in electricity usage

  3. Photovoltaics and the feed-in-tariff


Earlier we omitted an estimate for how much heat from the wood burning stove contributes to the home. After digging through some numbers from the Centre for Alternative Technology we came up with a rough number of 4000kWh pa (not far from the 3320kWh estimated by the BRE baseline calculator for the old gas fire). Then there are the solar thermal panels which contribute about 2700kWh pa to hot water needs. So all together the saving over the BRE baseline is 20% which is half the 40% we originally estimated, based upon the wood pellet boiler alone. This isn’t the entire story though because now 2700kWh pa is FREE from the sun. This element can be discounted from the running costs. The effective saving is thus 28%.


We know that annually our gas heating & hot water bill should be £1,250 pa. How much did we spend on making our home warmer via insulation and using the power of the sun? About £6500. Hence the saving of 28% is £350 a year off the gas bill. This is a payback of 18 years at 5.3% APR. Not bad but not exciting either.


Lets scrutinise the numbers again. Ours was an expensive investment in that we chose sheep wool insulation. That wasn’t cheap. You can get your attic insulated for FREE so we have slightly exaggerated the costs. We also included the cost of removing trees from the south of the property in order to boost solar gain. Over half that cost was contributed by the solar thermal panels though and these have no current government support mechanism.


What happens if we take the sheep wool & solar thermal out and assume free loft insulation? The cost falls to only £1750. We will have to pay an additional amount for that 2700kWh pa hot water in a higher gas bill. The energy saved drops to 20% or £250 per year. This investment pays back in 14 years at a 7% APR. Even better.


What about the solar thermal panels by themselves? They would have saved 2700kWh pa on the baseline of 34,231kWh pa. That is about 8% (remember that most of your heat load is for space heating, only a small amount goes into hot water and, of that, solar thermal contributes about 50-60% at best). 8% of £1250 is just shy of £100 a year. Payback is thus 37 years on a system that cost £3700. So, without government support solar thermal isn’t attractive by itself.


Moving on to number 2: electricity. We know already that we saved 28% on the usage (2900kWh pa versus a BRE baseline of 4100kWh pa). Cost per year of electricity at baseline would have been about £540. A 28% saving is £150 a year. What did we spend? About £1200. Thus the payback is about 13 years at 7.7% APR.


Finally, number 3: photovoltaics.  They cost us £13,500 to install. We got a £1000 grant from the old Low Carbon Building Program. Total = £12,500. Annual return is £1,600 from the Feed In Tariff (FiT) yielding an 8 year payback at nearly 13% APR. In fact the Feed in Tariff (as it was) was so lucrative that it almost pays for the ENTIRE project by itself. The FiT has subsequently been cut significantly in line with reduction in costs of the photovoltaic panels. Paybacks are now in the region of 16 years. To get that in perspective we installed photovoltaics on our previous home in 2005. Even with half the cost paid by the Low Carbon Building Program Grant it would still have taken 35 years to pay back the cost. We should look on the bright side.


So, what have we learnt? You can cut your energy bills by somewhere between 20% and 30% EASILY and save enough to pay that money back inside 15 years. At current interest rates that is much better than money in the bank and would be a very shrewd investment in your home. In fact energy saving is now a better investment than solar panels which give you an indication as to where your priorities should lie.


So, question: why if these technologies have a good payback did the entire Superhome59 project NOT have a good payback? Answer: simply put, “renewable heat” (solar thermal and the wood-powered boiler) have lousy-to-non-existent payback. They save a heck of a lot of carbon: a 90% saving in this case, but it wasn’t economic by itself.

 

But this is just the experience of one home. What do other people think? Figures from the Energy Saving Trust are somewhat more optimistic per technology:

 

  • Energy efficient light bulbs payback in 6 months

  • Loft insulation payback in 2 to 6 years

  • Hot water tank insulation payback in 1 year

  • Double glazing payback in 5 years

  • Heating controls payback in 2 to 5 years

  • Draught proofing payback in 3 years

  • Replace old boiler payback in 4 to 5 years

  • Cavity wall insulation payback in 3 years


We actually employed EVERY one of these technologies. We can’t explain the differences between our numbers and theirs. We wouldn’t read too much into it. There are far more pessimistic numbers out there. In 2006 the Royal Institute of Chartered Surveyors (RICS) ran the numbers and came up with this, very different, conclusion:

 

  • Cavity wall insulation payback in 5 years

  • Loft insulation payback in 13 years

  • Hot water cylinder & pipe insulation payback in 38 years

  • Replace old boiler payback in 38 years

  • Heating controls payback in 34 years

  • Double glazing payback in 124 years

  • Solar hot water payback in 208 years


Clearly experience shows that the RICS numbers are way too pessimistic given today’s gas and electric prices. Likewise our experiences suggest that the EST are slightly exaggerating their case.


So, bottom-line - was it worth it? Yes for insulation. Yes for saving electricity. Yes for photovoltaics (but ‘no’ if there was no Feed-in Tariff). No for solar thermal. No for wood-powered boilers (if you are on mains gas). Overall? Just about worth it in terms of money but definitely worth it for the intangibles.


In 2013 the Renewable Heat Incentive (“RHI”) rolls in for wood-powered boilers and solar thermal. Therefore these numbers will change and we will be re-writing this page all over again come 2014 – a year after the introduction of the RHI. We will not count our chickens however it can only get better for renewable heat. We should expect the payback periods to be reduced and the return on our investment to blossom.


All this and a lovely warm, modern, house to-boot. It’s a no-brainer. A few more facts and figures for you:

 

  • Estimated reduction in Carbon Footprint: >90%

  • Actual savings: >4.5tonnes pa

  • Minimum expected lifetime of the retrofit: >25 years

  • Total savings = 25 x 4.5 = 113 tonnes minimum resulting in a carbon cost of £347/tonne

  • Total home energy used per annum = 30,240kWh (comprises of stove 4000kWh, wood pellet space & water heating 20,600kWh, electrical 2942kWh & solar hot water 2700kWh)

  • Total living-space floor area = 124m2

  • Footprint now 243kWh/m2 pa*

 

*For a Passivhaus the total primary energy use for all appliances, domestic hot water, and space heating/cooling must be less than 120kWh/m2 pa.

What we will do next

 

We plan a solar conservatory for the rear garden but it would prove to have a very high cost for very small benefit. It can't be justified for carbon footprint reasons so would have to be a lifestyle/comfort choice. We have considered putting an air-source heat pump on the conservatory - just to tick that box! There is a plan to remove the bathroom over the garage and convert the space to have a larger bedroom and smaller en suite. This would remove some pipework from the garage ceiling. Thus the garage ceiling can be insulated from below to keep the living space above somewhat warmer. As part of this project we are considering doing a super-professional-insulation job of the over-garage living space. This might include interior wall insulation. This space is a big problem as it is always the coldest space in the home acting as a reverse radiator sucking heat our of our home and dumping it into the garage and garden. It is a hole we wish to plug.

 

The loft is another area we can improve upon as some celotex can go between the rafters and we think we could purchase some sealed pads of insulation we could move around between storage items rather than having fixed insulation. However we would have to move the TV aerial out of the attic as the foil-covered insulation would rob us of our TV reception.

 

From there on we are into the fantasy-areas. If we could we would refit all the double-glazing with Passivhaus-standard wood framed triple glazed units (starting with the north-facing side of the building).

December 2011: full thermal imaging survey

Thermal ImageIn late 2011 we performed a full thermal imaging survey of Superhome 59 both inside and out. This was performed across the weekend of the 2nd, 3rd and 4th December 2011. We used a Testo camera borrowed from Wycombe District Council Building Services via a joint project between Transition Town High Wycombe and the Wycombe Strategic Partnership's Community Carbon Taskforce. The survey can be downloaded here but be warned that this file is 15Mb:

The Sustainable Energy Academy & Superhome 59

We were delighted to have this eco-retrofit recognised by the Sustainable Energy Academy and became Britain's 59th Superhome in August 2010. The project name is "Old Home Super Home" and the title is reserved for old homes that have reduced their carbon footprints by 60% or more. We reduced ours by 90% if not more. Learn more here: www.SuperHomes.org.uk

 

     

 
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