Passivhaus Retrofit – Is it Worth it?
This is a guest contribution from Ron Marsh.
I'm reading and learning a lot about Passive Houses at the moment in readiness to start my own project. Finding a plot to build a new house on is almost impossible these days in many parts of the country. So, the other option is to retrofit an existing home. This is when my troubles really started. As hard as I try to crunch the numbers, they simply don't add up.
Since the Passive House Institute came up with the “EnerPHit” standard for existing homes, everyone seems to be ranting on about retrofitting the housing stock in the UK. It will save energy, save the embedded CO2, and save the planet. However, as far as I can see, the underlying reality is that this is not anyway near cost effective in most cases. Some further investigation is required.
I have therefore put together some thought provoking ideas about this in order to stimulate the debate, and openly challenge anyone to come up with a solution that will clearly show the boundary between “sensible” and “impossible” that can reliably guide anyone considering an improvement to their comfort and eco-credentials through their house.
“Anywhere can be retrofitted” is something I hear being banded about recently. That's true enough, it can. Just throw money at it and it can be done. There are loads of enthusiastic practitioners out there ready to help you, and a plethora of available products to assist.
There are some examples around, mainly housing associations, where they have retrofitted. Even with the existing inhabitants staying put while it happens. Very admirable. I can't see quite why they have done this yet, but time will tell. I am finding it difficult, however, to find any examples where a normal family have successfully attempted it, starting with their normal fully functional house.
What's at Stake if We Do Retrofit, and What Can We Do About the Problems if We Can't?
The contentious issue must be energy costs. They keep going up. There's no sign of them slowing down. Fuel poverty is biting at low income households.
Next, there's the planet. Climate change through excess CO2 generation. Almost everything we do makes more CO2. How can we stop this for future generations? Will it do any good?
And finally, the crunch question – Can your wallet handle it?
It has been suggested in some published articles/books that retrofitting can be more expensive than the house itself is actually worth. That's not a good start, is it? This depends on where in the UK the house is of course, but many northern cities have average house prices at around £100k, and in the affluent south, they may be £250k or much more. The cost of retrofitting is probably similar wherever you are, so that's the first problem. I've seen a few retrofit project totals mentioned on the web as a rough ball-park guide. One of £80,000 and one of £110,000 come to mind, which are probably indicative. But even though, if you invest between 30% and 120% of your house's value in this idea, will that add to the street value of the house if you were to sell up? That's one for the estate agents to answer, but when the same looking house in the same street is up for sale, will a potential purchaser see the increased value and be prepared to pay double the price of the one next door? Will they be able to get a mortgage? Will they want to live in a lower class area relative to the amount they've spent? They will make the same calculations themselves, and may decide it's not worth it, maybe less so if it doesn't tick all their other boxes perfectly as well, and that may make a retrofitted property unsaleable. This problem reduces, as the area becomes more affluent, and because the value in most houses is actually in the land rather than the bricks, there must be a price point where it gets close to the same cost of knocking it down and doing a proper Passivhaus rebuild. You can build a nice new Passivhaus for about £150k. (Denby Dale as an example)
Even the Passive House Institute themselves have a much lower standard for retrofits (called EnerPHit) because it's so hard to do it properly on an existing building frame. That speaks volumes in itself to me. What are they thinking of? Knocking down the original house and rebuilding it to the best Passivhaus standards, would save more energy than by retrofitting it. You'll end up with a new house into the bargain, and with a better design for modern living. But even that option will cost a relative fortune, far beyond what normal people can afford.
The simple fact is this; retrofitting allows you to keep the same house. It might save a little bit of CO2 (less than £1000 worth -see below). But that's where the fantasy stops.
Realistically, retrofitting (or rebuilding) is only affordable for the well heeled green householder with money to burn. Where will a normal home owner in this current climate of austerity find upwards of £80,000 to insulate their home, with the understanding that they will save some of their energy bills. The average energy bill is in the region of £1500 of which, so I am told, 61% or £915 – is for heating; the portion that a Passivhaus retrofit is mainly concerned with. If you could wipe a £1000 off your bills it would be great, but even with a 10% rise each year, it's going to be some time before taking out a loan for £80,000 is eroded away. The remaining £500 bill for hot water and domestic electricity is easy to deal with in smaller bit-by-bit upgrades by installing solar panels, changing bulbs or getting an A+++++++ washing machine etc. Even after retrofitting, you won't get a ZERO bill, so you are going to save something like £750 a year if you are lucky.
So here's the crunch. Your new heating bill is, say, £250. Interest on £80,000 at a special Green Government rate of 1% (that I have just invented!) comes to £800, and that kisses goodbye to your £750 retrofit saving in the blink of an eye, and unless you can plough in something like £3000 extra income per year for the rest of your working life at the expense of your already shrinking pension pot, your children will wind up with a minus £80,000 inheritance! My maths isn't brilliant, but unless I've made a big mistake somewhere, alarm bells need to start ringing, don't they?
Front-loading your energy bills to the tune of £80,000 is a big lifetime risk to take. Especially when you can't afford it.
What's ironic, is that if you did have a zero energy bill, all that would actually improve is your standard of living. You would just spend the money elsewhere instead, probably converting it into more CO2 via a trip or two to New York . . .
We will stay warm enough one way or another whatever happens to prices. As more people start choosing from the “heat or eat” option, we get closer to anarchy and the Government are closer to getting voted out. They run a very thin line with a vested interest. A lot of the green building movement are talking about lobbying the Government about this stuff. Nothing is going to happen that makes retrofitting a realistic possibility for the Government to buy into. As you can see, the cost of doing this to ~15 million homes at ~100k a pop is in the order of £1,500,000,000,000. Er, how much? The Social Security and defence bill combined for the UK plus the cost of HS2 is less that 20% of that total . . . so if you want to see the back of austerity, you'll have to stick to the Government adding £120 onto your energy bill towards their minimal contribution to renewable energy.
Don't forget that there are some people living right on or below the breadline. They can't afford to heat their homes to a healthy standard as it is, so spare a thought for those people. They probably need a passive home if anyone does, and certainly won't be able to fund any retrofitting themselves. Then there are all the landlords out there. The buy-to-let market is quite huge. It's hard enough to squeeze a replacement fridge out of many a landlord, so I can't see them investing in any form of retrofitting. Then there are second and holiday homes. I have no idea of the size of these groups, but it must be a significant number.
Is the Energy Problem Going to Go on Forever?
Extra cheap and clean CO2-free energy is starting to loom on the horizon. Lockheed are suggesting that they will have cracked nuclear fusion within 10 years and you can have a safe nuclear power station that fits into your back garden! Unbelievable maybe but decide for yourself; (or Google “Lockheed fusion”). Fusion apart, there are big changes in solar farms, wind farms, and wave things. It won't be that long before some serious renewables will be coming on tap.
There's another way of offloading the high cost of retrofitting; Fill your roof, walls, and garden with PV. If you “over harvest” as it's called, you can potentially generate your total energy bill and get paid for doing it, giving 20+ years of trouble free energy. The average cost of a 4kw system is about £8000 – so for £25,000 you could virtually wipe your bills out of the sky, literally! Panels can be flat against a wall now or point off-South and still produce power. Your provider can advise on this.
The Feed-In Tariff is slightly less for over 4kw, but not to be sniffed at and could still knock a big hole in your total energy expenditure. I believe you may have to get planning permission to mount panels away from your house though.
Spare day time PV (while out at work you don't use much electricity) can be used to heat water, which could be stored to run underfloor heating. At night you normally buy back from the grid, but you can also store daily excesses in Lithium-ion batteries to use at night now while you panels are sleeping. The funny thing is that FIT assumes that 50% of your generation is used, and 50% sent back to the grid. So you can actually use 100% of what you generate AND get paid for the 50% that NEVER goes back to the grid. Amazing! Or invest in a solar farm – there's plenty of those popping up, due to the Government incentives. And more exciting is that there are transparent panels on their way that can also act as your windows, and PV that works after sunset! The future's looking bright in the mid term.
And as far as making BIG green energy is concerned, a modern wind turbine costs about £1.5 million to install, and it pays for itself in 3 years. It generates enough energy to run over 1000 houses pretty much for free, and for 25 years. I was told that by an Ecotricity rep. The one they have in Norfolk runs 1200 homes for virtually nothing now, although the company reinvests the money they get into more turbines. They just need more customers to speed things up. We would be better off clubbing together in a community and buying one or two of those. That is literally what has happened in Swaffham – they actually asked Ecotricity to build another one right on their doorstep! Only 2% of the UK is currently choosing 100% green energy providers, although since the recent price increases Ecotricity have been inundated with new customers, so more turbines will be popping up soon. The green snowball is gaining size and momentum.
It's looking likely, that current energy prices will be regarded as a blip, because things might be getting better sooner than we think.
Don't get me wrong, I love the Passivhaus idea. I still want a Passivhaus. I believe in it. I believe in preserving humankind and the environment. I want to live in a perfect comfy atmosphere with no worries if the power does turn off.
All new houses should be made like this by law from now on. All major extensions should meet these standards too. And any buildings that actually need to be demolished, should be rebuilt this way. The additional cost is minimal when it's a new build. This can be quickly recovered in energy savings and other benefits and is a good investment. It's good to be cosy, and have a nice environment to live in. In an ideal world we would all do it tomorrow. The planet also needs saving, Makes perfect sense at that level.
So What About CO2 and the Planet?
What is the real impact of the CO2 that our energy use is creating? And what could that retrofit do towards it? Well, using the Climate Care website, you can pay for the damage you cause in CO2 and become guilt free for surprisingly very little outlay. An average house's annual CO2 generation through energy use can be offset for about £60 a year, and using BP's Target Neutral website, you can extrapolate that the cost of off-setting the building of a whole house from scratch would be less than £1000 worth.
I believe the real retrofit issue goes back many years to the time when central heating became widely available, around the late 60's. Your house was warm and it didn't cost much to keep it that way. Then we started filling the cavity walls and adding secondary glazing as energy prices started rising. Now, it costs quite a bit, so it's worrying for us all, and there's not much more we can do to improve our houses. And now, retrofit has arrived on the scene to save us. But most people are not really worried about embedded carbon and greenhouse gases. They still worry about the £pound in their pocket. When someone can twist their arm into retrofitting their house, they'll do it. Solar PV is still not worth it if you just buy the panels, but when the Government twist your arm with the Feed In tariff, no one gives a moment's thought about the production of green energy. They say “Look how much money I made from my FIT this quarter”. It's an investment to them. Not a solution to anything.
We are worrying about the future, yet retrofitting is the unobtainable holy grail.
Having come from a cold cave, I don't think the human race is in any danger if we don't all “Passivy” ourselves quite yet. We've got much bigger fish to fry, before the human race does.
But I don't believe that retrofitting is going to help anyone, other than builders themselves by generating unnecessary work in return for a very dubious pay-back.
Someone did mention that retrofitting can create jobs etc, and this would be true, but someone still has to pay for it in the end. It doesn't just grow on trees. HS2 is costing every one of us about £1000 alone, so trying to calculate the effect of retrofitting our housing stock as an investment in jobs is pretty much impossible to contemplate outside of the Government's own plans. It's simply too complicated and would require a total change in the way the country is managed. It's not going to happen.
I still think that a certain amount of cheap, added insulation can make a temporary cost effective contribution here and there to an older house, but it still has to be carefully costed out. Have a look on the internet, and you'll find all sorts of home made solar panels made from computer fans, coke tins, cardboard, and pallets. These are cheap. They can save money if you are that close to the financial abyss. We should be doing more of that sort of thing while we wait for the future. Every square metre of sunshine has about 1Kw of energy in it, waiting to be sucked up.
So, my answer to retrofit? Don't bother even thinking about it. Unless demolishing the building or wasting a load of money is what you are into. Just throw some cheap add-ons at your existing house (new boiler, solar, loft/wall insulation, draught strips, new bulbs, thick curtains, educate the inhabitants, buy A+ when replacing consumer durables, home made solar collectors, etc) and make sure no one is left in financial poverty if the bills do go up for a few years until the renewables change things completely.
As with self builds, there might be some mileage in retrofitting your own house, but this is going to be very hard for a self builder to contemplate, because a lot of experience is required to overcome many of the retrofit nightmares lurking in the existing house fabric. If that's what you fancy, then flatten it and start again.
Pollution in Shanghai
And the Planet? Can We Save it?
Passive houses will not save this planet of ours. With China and the like filling the air with CO2 at a rate of knots, what the UK, and any other passive house aware country can counteract with a few bits of glass, plastic, and concrete is pretty much microscopic. The money should be thrown into green energy instead as fast as possible. Governments should, however, change planning rules to Passivhaus levels for all new building work with immediate effect to gain the most from that future. That is the best solution we have until we treat the problem globally.
Individually, we can all do our bit too by not going on planes, becoming vegetarian, and riding a bike. The carbon saved from those activities alone is enormous in itself and easy to do. And it will save you a lot of money – enough in fact to pay for your current energy bill without even having to flinch.
Get yourself some solar panels, revisit your insulation levels, and change to a 100% green energy provider. Then off-set your CO2 and you can be warm and squeaky clean at the same time, and living comfortably in the house you probably already love.
You might, of course, skip all of what I have suggested so far, and simply look for a ready made Passivhaus if and when the chance becomes available. But be warned, I have noticed that the retail price of a few new ones I have seen is reflecting the savings you might make in the future. Someone out there is trying to get you to pay up front for your future. If it costs 5% more to build a passive house (according to the Passive House Institute themselves), then buying a new one should cost no more than 5% extra on top of a comparable house. And that's the building cost, not the actual cost of the house. A £300k house in the South East say, with the assumed building cost of about £150k should therefore cost no more than £317k in a full Passive overcoat and with 4kw of solar on board. Toasty! (5% x 150 = £7500 4kw PV ~£9000 Total £16500) So don't get caught out by the sales pitch.
This of course, explains the final reason why retrofitting is a waste of money. Just sell up, and buy a new one as soon as you can. They are few and far between at the moment, but those in the know have the advantage of knowledge, and there will be more opportunities to get one as time goes by, but before the rush comes. If it even does.
So, that's pretty much “Check Mate” isn't it?, but I challenge anyone to calculate more accurately whether retrofitting a bog standard house could be worth it at any level. And if it is, how on earth it will be paid for by the average person. And if it isn't worth it, say so now, and let's all move on to NEW passive houses only, and get that working even better, just in case we need it.
So is Retrofitting an old house worth it? No, not from what I can see. For once, it's not about the technicalities of doing it. It's about the practicalities of doing it. And it fails on that count very convincingly.
That's the prosecution case complete. Will the defence now please step forward . . .
About The Author
I have no formal qualifications in this area of expertise or accounting. I am however widely read, have some experience in self building, and have been on an alternative energy course. I am passionate about sustainable living. My glasses are not rose tinted and I can see through things.