This image is a slide from a futurebuild 2020 presentation by the lead architect of the team that won the Sterling Prize in 2019 and many other prizes besides. This project, Goldsmith Street in Norwich, is a Passivhaus Superstar. it was interesting that this architect said it is not necessary to use Passivhaus Approved products. However, he said it was necessary that the builder was required to prove all his work was carried out well. Air tight had to mean air tight, no temporary sticky tape over the cracks.
This is a quote from one of the speakers:
Mechanical Heat Recovery Ventilation, when it works, is brilliant saving a lot of money for a small investment. But MHRV needs maintaining. One customer who is very pleased with his MHRV says he pays £25 a month by Direct Debit for all his heating, cooking and hot water for a 5 bedroom house with a flat incorporated for his son.
He questioned my doubts about MHRV. I said my concern was I had been persuaded that shutting a MHRV unit away in a corner of the loft where no one ever changes the filter can stop it working, meaning no energy saving and possibly toxic air if no fresh air gets in.
He told me that his MHRV unit is very accessible and as well as changing the filter 4 times a year, quite expensive but very simple, they take the filter out every fortnight and vacuum up the lint that collects in it, rather like cleaning a tumble dryer filter.
He said it is amazing how much lint collects in only two weeks. His MHRV saves him a lot of energy and makes his air lint and dust free throughout the house. It is as if the MHRV does half his vacuuming for him, so it makes sense to vacuum the filter frequently and change it before it clogs up with pollen and so on that vacuuming cannot remove.
Insulating a home with a basement.I have attended many exhibitions including workshops at Ecobuild in March 2019. I have also kept in touch with some clients to find out how their energy saving performed. Usually not as well as hoped.
The question is: What Works well?
Experts at Ecobuild said keep your money instead of spending it on kit because less kit saves earth's resources, and keep your money instead of spending it on energy because less energy is best at reducing global warming.
Photovoltaics generate the most facing South at mid-day, but that is when we don't need much electricity. There have been instances where solar and wind powered electricity combined was more than was being used and the wholesale price went negative. Energy had to be wasted.
One answer will be to charge up electric car batteries while they are parked up during the day, instead of buying petrol and instead of selling electricity cheaply to the grid.
Perhaps, one day, company-owned electric cars will be charged up from solar panels while they are parked outside the office (while the wholesale price of electricity is negative); the computer will sell electricity from the car batteries to the grid when the wholesale price is high enough and the computer will make sure the car has enough power to get the worker home and back to work in the morning.
In this imagined scenario the company will own the car, its batteries and the power it puts into them. And it will sell power as well as its usual business.
Until then the rest of us need a Tesla Powerwall and a Tesla car which both cost a lot of money.
It is very easy, when extolling the virtues of alternative energy, to forget that the iron used to make the kit was mined in Australia and it took a huge amount of coal and water to turn it into steel as well as oil to transport it around the world. The same for the copper pipes, the enamel, the plastics, the aluminium and the copper wiring. We use a huge amount of energy and water to turn earth resources into manufacturing materials. Buying kit created pollution and increased global warming. Changing a component or throwing the whole thing away and replacing it creates even more.
There is growing doubt in the UK that we could ever save as much energy and CO2 with alternative energy generation as we spend creating, maintaining and replacing the kit. Neither is there much certainty alternative energies could ever, really, save us money.
We must use less energy, not spend, spend, spend on alternative energy. Recovering energy from cooking and body heat with MHRV and softening cold snaps and hot snaps with thermal mass are surely the no-brainers.
I'm not selling anything here. This page is my conclusion and recommendation after years of exhibitions and going back to customers and asking them how their energy efficiency choices had worked out.
Most customers had a warm basement, even without heating, but often the rest of the house did not work out as well as expected.
Insulating Concrete Formwork ICF
I built with ICF for about 8 years but there were two major reasons I stopped.
There is a lot of talk about improving the quality of house building by building homes in factories and delivering them in panel form and erecting them on site.
I can see a lot of benefits but the sadness is that panels will be lightweight and have no thermal mass. These homes will need more heat on the coldest days and more cooling on the hottest days than my preferred choice using concrete and thermal mass.
I added this next piece over Christmas 2020 from somewhere within tier 4. I expect to revise it a few times.
Do Building Regs require insulation throughout?
Building Regs would seem to, but actually we have to pass the SAP or SBEM calc test and there could be an exception.
Researching this during a conversation with a client, who paid me for my £125 service, I found the following: and this seems to tie up with a couple of clients who built their basements without insulation everywhere.
The guide above, Thermal Mass Explained, states on page 15 that thermal mass capacity is limited to the first 100mm. This seemed unfair to me, especially in light of the fact that the failure of ground source heat pumps prove heat passes through soil very slowly - so why shouldn't all the concrete and the soil beyond count toward basement thermal mass?
I looked for proof that very dense concrete is an insulator by virtue of the fact that heat passes through it slowly.
Without the success I hoped.
has a link to a page with a link at the bottom to a
free spreadsheet produced by the same people.
Please investigate this for yourself if SAP calcs are a mystery to you.
The little revelation I found is that from an insulation perspective the soil beyond the concrete structure can count toward the insulation.
The soil beyond the basement cannot count toward thermal mass but it can count toward insulation.
The simple conclusion seems to be that basement floors don't necessarily have to be insulated because they always have at least 2m of soil beyond them.
That means I can change my sketch at the very top of the page by removing insulation underneath and that allows me to remove the footings for face brickwork as well.
A slide from a presentation at Futurebuild.
We should be asking ourselves what actually works?
First and foremost, good workmanship - which might require continuous, effective inspection to refuse to accept anything sub standard - works a lot better than rushed work and sub standard materials.
Note the quotation above about the mass built house designed to 0.16 but built to worse than 0.30 by a national house builder.
And the other note above the six-point sketch of the Sterling Prize-winning homes "necessary that the builder was required to prove all his work was carried out well"
If you are a self-builder you have the chance to demonstrate to the country that carbon, energy use and emissions can genuinely be greatly reduced. And that it need not be expensive to do so. But how?
These next 2 examples are going off at a bit of a tangent:
They are photos of insulation added to the outside of a property (that I am 're-arranging' in my spare time), all paid for by the Green Deal Scheme entirely free to the lady on benefits who lived there before I bought it.
The workforce may have only drilled their holes a bit too shallow but they did so all over all the external walls, and the gap, which is open at the top, allows all the heat to escape before it reaches the insulation layer that was supposed to keep it in. (The bits of spray foam were put there by me before I decided to replace a window frame).
You probably cannot trust anyone unless all their work is independently inspected and approved.
ICF is bad (my many reasons not to use ICF are two pages further on). Timber frames and SIPs are poor because they don't store energy. Heat pumps are too expensive or don't work unless the heat source is a large body of water.
What worked best of all, and for less cost, was thermal mass with no cold bridging, excellent air tightness and recovering heat.
The best thermal mass is dense concrete. Cement in the UK is responsible for only 1.47% of our carbon emissions (compared to an average 6% worldwide). Yet concrete can massively reduce the 28% of our emissions that are due to domestic heating - and likely to rise as we install more air conditioning unless we do something about it.
What we need from the heating and cooling of our homes is the ability to lose body heat at a comfortable rate. We don't want to be too cold and lose heat too fast, neither do we want to be too hot and unable to cool down. And daytime and night-time might require different room temperatures.
Thermal Mass is the ability of a heavyweight material to store a lot of heat and release it slowly. The denser and the least conductive the better.
Cast insitu concrete, brickwork and stonework are all good.
Concrete blocks are less dense and so less good. Beam and block is less effective than concrete cast in place.
The experts at the Futurebuild workshop discussed the high carbon cost of materials and equipment as well as energy. Apparently, specifying up to 8 times the equipment needed is not uncommon. Neither is it uncommon to completely replace a whole unit instead of replacing just the part that failed. This all wastes carbon emissions and precious water along the supply chain.
They went on to explain that sourcing all the building materials and all the materials your equipment is made from, as well as all the transportation; and the end of life costs in removing and replacing anything all add up toward your Whole Life Carbon. A concrete office block completely gutted and refitted when a new tenant moves in and then demolished after only 10 years to be replaced by an even bigger concrete tower, is a terrible waste of carbon.
One of the expert's teams had to quantify the carbon in a new public building. They found that a lot of the timber was Canadian but it had been sold and moved to Southern USA before being purchased and transported to Britain. The total carbon was more than twice Scottish timber that only travelled 300 miles or so. In comparison, how far would your concrete travel? The aggregate, 77% by weight, might be quarried where they batch the concrete. If so usually a maximum of only 20 miles. The cement: a 15th of your concrete might have come from Port Talbot and another 15th from Greece. Another 15th is the water that only travelled as far as the truck. Overall, concrete is greener than many suppose.
Some of the best results the experts at the workshop got anywhere were concrete used where its useful life would be expected to exceed 150 years - which could be your house. The carbon investment in a concrete house becomes insignificant annually if it will be in use unchanged for 150 years.
Another cause of carbon waste the experts were keen to make clear was the effect on Whole Life Carbon designing a building and its services to fully meet the demands for energy during the coldest and the hottest times.
Your MHRV supplier might well try to supply you with an average one air change per hour with ducting to every room. But will this be too much when everyone is out or asleep? This sketch came up first page in Google: I think the experts would say this is over-engineering and over-selling.
Plus, the exhibitor at the HB&R Show cast doubt that MHRV would work after the first couple of years.
Looking carefully at every example he might be right. In every example this supplier has hidden the units deep in the loft where they are least likely to be maintained properly.
The experts said that in order for every building in the land to get enough mains energy for air conditioning during the hottest few hours a year and full-bore heating during the coldest few hours a year, the extra national grid infrastructure and extra building equipment and services and energy certain to cope are twice what is required on the other 363 days a year.
They impressed upon us that if our buildings can only cope with 95% the peak demand during the coldest and hottest few hours a year, then the total Whole Life Carbon for everything required (mains supply infrastructure, equipment and energy) is halved.
And the way to smooth out the need for peak energy is thermal mass.
One of the experts said that his Victorian, London home, refurbished to maximise thermal mass, air tightness, insulation outside and heat recovery ventilation maxed at 25oC throughout the heat wave last year. A new build could do even better.
But when I returned again in April 2017 to catch up on old times, their bills were £1,000 a year for energy.
Something had gone wrong. Actually, two things in particular seemed to have gone wrong.
Until March 2019 I was excited by solar powered panels on the roof. But it was telling that at Futurebuild many heat pump, solar panel and Tesla Powerwall suppliers didn't show this year.
The problem is that solar power in Britain is at its maximum when demand is at its minimum. Until we can store electricity solar doesn't have much value.
This BBC correspondent explains quite clearly why domestic wind turbines are sadly a waste of money as well.
The ground source heat pump and the air source heat pump guys have been trying to let you believe that the efficiency in Summer is so good that even in Winter you save money. But put on the spot many can't tell you that you would save anything on the coldest days when you need the most energy.
They are also sneaky because the savings they claim are against electricity whereas most homes are heated by cheaper gas and oil, so the actual savings for most are far less.
But if, at exhibitions, you ask how much does it all cost, it seems to me that those talking in the realms of £7,000 are the ones who struggle the most to convince you that you will always save energy; while those talking about £20,000 are very confident you will save energy all the time, but they cannot promise any financial return on your investment.
However, saving money and saving energy aren't quite the same when it comes to renewables.
Maybe because cheaper could be free over 7 years, because of RHI.
The Which? magazine has a guide. Note that RHI is aimed at those 'who are off the gas grid'. The reason why might be lower down this page.
Perhaps the Renewable Heat Incentive, RHI (Ofgem web site), will cover the whole cost of a small installation more easily than it will cover the whole cost of an expensive scheme; except that with a cheap scheme you probably still need some expensive, carbon-emission-rich energy from the grid and another heating system as well for the days a small heat pump cannot cope.
£20,000, I'm not saying that is what yours needs to cost, might only be partially offset by the RHI yet more likely to provide all your energy cheaply and with substantially reduced-carbon-emissions. But only cheaply if you ignore the huge investment and only lower greenhouse gas emissions if no refrigerant gets lost during servicing.
£4,000 and the RHI might cover the heat pump cost completely, but you might not get much free heat that way and you could still be buying expensive energy from the grid as well.
It seems to me, that ASHPs too small for the job and GSHPs without access to enough soil struggle in cold weather - especially if your home got cold when the temperature dropped suddenly outside and you want a lot of heat fast.
Whereas a larger heat pump heating a house that is well insulated and protected from a sudden drop in temperature outside might cope adequately at all times - but if your home is well insulated and well protected with thermal mass do you even need a heat pump?
Another technology that caught my attention (in 2018) is Seasonal Thermal Energy Storage. STES.
Icax says on its website: "It is a characteristic of earth that heat only moves very slowly through it - as slowly as one metre a month."
Icax tells us what we hear all the time, that it is very expensive to store electricity. But, they say, it can be virtually free to store heat. What they seem to promote are two systems both with coils alongside each other buried in the ground.
Should we be storing heat in the soil beneath our basements?
We would need the heat to be very deep beneath our basements so that it didn't come out into our habitable space too early when we didn't want it to.
If you have already dug 3.5m down the only safe way to go further might be with piles or a borehole. If you hit water then any energy you tried to store would be washed away instead.
I'm not sure storing energy underground could be viable.
Finally, my recommendation.
The benefit of the concrete house is its air-tightness and thermal mass. Once up to temperature, you hardly need anything to keep it there because of cooking, washing and your own body heat.
You still have to choose your domestic hot water provision. The cheapest might be electric hot water heated partially by solar energy and brought up to temperature on demand by electricity. London is going to forbid immersion heaters soon. Storing hot water is wasteful because stored hot water soon goes cold.
The environmental benefit of concrete is not in how much renewable energy you get from an investment of tens of thousands of pounds, but how much less energy you use during its incredibly long life time than building any other way.
I am convinced that once built and lived in, my proposed home would require the least energy to keep it warm and cool compared to any other scheme, unless that scheme cost several times as much.
You might not like any of my thinking. Fair enough. I'm not selling it, I'm only sharing it.
2018, 2019, 2020 and 2021.
My recent copy of "The Economist" has an article saying that at mid-day during our Summers coal and nuclear power stations need to switch off, which puts up their costs, because solar panels on houses produce much of the very low level of power needed at those times.
So, it now seems more reasonable to me that electricity from the grid costs 18p but we can only sell it to the grid for 4p. When we want to sell electricity the grid doesn't need it as much as when we want to it buy from the grid in Winter at night. Simple supply and demand.
Indeed, if we have many more solar panels, then perhaps at very sunny moments panels will try to sell more to the grid than the nation is using at that moment. What happens then? Does stuff explode? Perhaps the grid will have to refuse to buy solar electricity and we will have to do something else with our excess power.
This brings me to the unanswered points in my graphic at the top of the page.
We should generate as much solar power as we can. But we should not be selling it. We should be storing it until we need it ourselves.
The next big emergency has to be air pollution and the particles from petrol engines and diesel engines but, I read, twice as much again from log burning and coal burning, which we choose for the theatre of a real fire in our living rooms. Fine particles from these three sources are now being blamed for causing stunted lung growth in our children and dementia in our elderly.
Twice as many damaging particulates are produced by fires as from traffic though, of course, in most areas fires aren't as concentrated as cars in cities, particularly at school gates dropping off and picking up the very children the particulates are harming most.
I have spent today looking into charging electric cars from solar.
I found a useful starter guide on Youtube by the Red Dwarf and Scrapheap Challenge star: Robert Llewellyn, here.
With all the kit: electric car, Tesla Powerwall 2 and solar panel photovoltaics - and the grid, you charge the car first with solar electricity, next with Tesla stored electricity, third with economy 7 electricity at night and, only if you must do you use standard tariff electricity. He says he hasn't used any standard tariff electricity despite having two electric cars to charge.
Economy 7 costs about 8p a unit whereas standard tariff might be 18p.
If the Tesla Powerwall wasn't fully charged by solar you can, or soon will, charge it with economy 7.
In the video, RL said that over previous weeks he had charged the car with 320 miles directly from his solar panels. My petrol car would cost £50 for that much petrol. He has also charged the car from the Tesla Powerwall that was itself charged from his solar panels. All that saved petrol has effectively gone into his pocket to repay his investment. Financially, it looks like you could save money over the lifetime of the kit.
Air pollution and carbon emission-wise, with no petrol and no log burner he is saving our planet and our children while many of the rest of us are causing them both harm.
It might be that over 10 years some of us would save money having a Tesla Powerwall and charging it at night with economy 7 electricity even if we did not have any solar panels. That would benefit the power generators because you would use your battery power during standard tariff periods, daytime, and the generators would have a more even demand over 24 hours. All your grid electricity could be 7p a unit cheaper. Your car could cost 10p a mile less to power.
I found talk that in future we might be paid to use the battery storage we own. We might be paid to sell stored electricity to the grid, at the times the grid is trying to avoid firing up another power station, more than the electricity cost us the night before on economy 7.
Everyone is different. As far as I can tell, back of an envelope savings might be:
Do you know how the Gilets Jaunes protests started in France? I heard on the BBC that a health visitor working in a rural area was incenced that President Macron put up the cost of petrol to subsidise the cost of electric cars.
She complained that only the rich could afford an electric car so her struggling to provide a service to the needy living miles apart in the countryside was put at risk because she, scraping a living, was having to subsidise the lifestyle of the most wealthy living in cities.
From DIRECTIVE 2010/31/EU
Nearly zero-energy buildings
1. Member States shall ensure that:
(a) by 31 December 2020, all new buildings are nearly zero-energy buildings;
2. 'nearly zero-energy building' means a building that has a very high energy performance, as determined in accordance with Annex I. The nearly zero or very low amount of energy required should be covered to a very significant extent by energy from renewable sources, including energy from renewable sources produced on-site or nearby;