Electric Heating – time to come in from the cold?

While there are well-established technologies to produce electricity without fossil fuels, decarbonisation of heat is struggling to get under way. Recommended strategies include expansion of low carbon networked heat and possibly the decarbonisation of gas – though these are still only happening at a scale (and with dubious carbon credentials, see PH+ Iss 15 – district heating). However, the commonest proposed means for decarbonising heat is via electrification.

Electrification of heat raises a number of questions about the ability of our power systems to produce enough low carbon electricity and their capacity to transmit it.  But it also represents something of a u-turn in building services design.

Electricity is still generated in large part from burning fossil fuels – including some high-carbon coal — in power stations that lose more than half the energy as heat.  For this reason electric heating – particularly direct electric heating – has had a well-deserved reputation for being high carbon and inefficient, to be avoided or replaced as a matter of course.

But things are changing – very fast. Thanks to Passivhaus in particular, fabric heat demand can be dramatically lower than it was in the ‘bad old days’ – and electricity is decarbonising at a pace: the UK has recently even enjoyed a couple of entirely coal-free days of generation.

Is it time for a rethink of the place of electric heating?

Click to view or download the pdf Together in Electric Dreams, written for Passive House Plus (issue 19)

 

 

 

Deep retrofit – the big prize?

Simple home energy efficiency improvements (such as new boilers, cavity wall insulation etc) can bring valuable comfort and health benefits to the occupants of inefficient homes – especially those in fuel poverty – as the last article revealed (see here). However, energy, carbon and bill savings tend to be modest, rarely topping 15% or 20% – and sometimes energy use actually increases!

If housing is to contribute its share of the 80% cuts in carbon emissions this country is committed to, in order to play is part in tackling climate change, retrofits will need to go deeper – a lot deeper. But will occupants benefit from the extra work? And is it affordable?

In the first part of this article we looked at the damage fuel poverty and cold homes do to occupants’ health, and found good evidence that when these twin evils were tackled, occupants could enjoy measurable improvements in their health. Encouragingly, some local health bodies are recognising this and investing in home retrofit to help improve people’s health.

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Passive House goes large

Passivhaus is no longer just the preserve of the self-builder: more and more large Passivhaus schemes are being announced. These include both non-domestic buildings, for example in schools and universities,  and multi-housing schemes, generally in the social rented sector, though sometimes with a portion for private sale.

In this article for Passive House Plus magazine I looked at some of the economies of scale available on larger Passivhaus projects, and some of the obstacles that larger schemes may run into. Also, following from my previous article on the cost of Passivhaus, I looked a bit further into the economics of Passivhaus from the point of view of developers and owners – in both the domestic and the non-domestic sectors.

Read the article in pdf here: Passive House goes large

My thanks to Passive House Plus for the use of this document.

The cost of building passive

Passivhaus (Passive House) is often thought of as being “too expensive” for the mainstream. There are some designers and developers however who are managing to shave the capital cost premium down to just a few per cent – or even zero.

In researching this article for Passive House Plus I learned that the extra costs, where they are incurred, seem to derive from two main sources:

  • Passivhaus components tend to be more expensive than the “conventional” alternatives – though this difference is diminishing all the time; and
  • There is a “learning curve” in first (and probably second and third) Passivhauses for any team, where designers and contractors alike need to spend a bit longer working out how to co-ordinate their activities to ensure that details are buildable, and that built quality matches up to the standards sought.

The extra costs are mainly up-front; looked at over the building’s first decades of lifetime, running cost savings – including maintenance, and even cost associated with tenant dissatisfaction – start to pay back the initial investment.

Of course a key question is “costs compared to what?” – and as statutory building standards edge upwards, you might expect the “standard” and Passivhaus build costs to converge – thus, for example, mechanical ventilation is increasingly commonly installed in non-Passivhaus dwellings, simply because Part L of the building regulations is looking for more energy efficiency and hence higher airtightness.

However, a couple of caveats:

  • Mainstream dwellings built even to high notional standards may employ cheaper construction “models” with less quality control, and therefore, leave bigger performance gaps; and
  • Passivhaus is offering more than just energy savings, it is also concerned with comfort and occupant health – something that has clear value, but is perhaps hard to price in the context of a shortish article.

I was particularly interested in the perspective from some of the people I spoke to, suggesting that insulation (literally!) of occupants from rising and unpredictable energy costs was not only attractive to owner-occupiers, it was also attractive to landlords and to lenders, as problems with soaring energy bills appear to be playing an increasing part in rent and mortgage arrears – making a Passivhaus building a better bet for investment.

Several people suggested to me that if building standards (and testing standards) were set higher, “levelling the playing field”, this would reduce the competitive advantage of low-efficiency, shoddy building – and with it, reduce the cold wind that whistles though the performance gap and straight into occupants’ wallets.

Unfortunately, to bring about this kind of improvement, I can’t help feeling big developers would have to devote less energy to lobbying for the status quo, and more to changing their modus operandi. But with the first record of a Passivhaus building (in Frankfurt) offering heat “too cheap to meter”, customers may yet demand the same here.

Read the article in pdf here: The cost of building passive

My thanks to Passive House Plus for the use of this document.

Allowable solutions – who are they trying to kid?

This is by way of an open letter to DCLG – which I sent as a covering letter to my response to (questions 1&2 of) the allowable solutions consultation – see previous blog

“I believe the whole idea of (1) “zero carbon” and (2) defining this or any standard not by how well the subject of the standard performs, but how many other people can be bribed to perform well on its behalf, is dreadfully misguided.

If you want to reduce the carbon emissions from new homes, then reduce the carbon emissions from new homes. Don’t reduce them some of the way to your target, then faff around erecting huge, complicated structures to reduce emissions from sectors other than new homes, and then pretend to yourselves and the world that somehow the new homes are low or “zero” carbon. Manifestly, they are not. What a colossal waste of effort!

If it isn’t possible, practicable, or affordable to make a new home zero carbon on-site (and it almost certainly isn’t) then for heavens’ sake don’t carry on pretending to yourselves or anyone else that it is. As you have found, the pretence requires a positively rococo structure of pretend emissions savings – your “allowable solutions” —  cumbersome, inconsistent, full of internal contradictions, and beset with potential loopholes.

And worse, what a colossal diversion of yours and the industry’s precious time and energy. All this effort going into refining the way you will trick out this delusion with regulations, price caps, verification procedures etc etc, when:

a)     the net impact on carbon emissions overall will be minimal (how can you ever know an action is truly additional, especially if people are competing for the cheapest actions – which, naturally, would be the ones most likely to happen anyway), and;

b)     you are incurring a huge opportunity cost in terms of effort, time, expense, and individual and corporate head-space – meaning the impact on emissions from new homes will probably be to INCREASE them relative to what they could have been, had you and your predecessors focused on reducing home energy in the first place.

Although mass housebuilders are notoriously uninterested in producing a high-quality product, seeing as they can sell what they produce anyway, given the housing shortage prevailing in this country,  some landlords/developers are now starting to take an interest in delivering really high quality homes. A significant number in the ‘affordable’ and social rented sectors, and now some building speculatively for the private market, are building or actively planning to build to the Passivhaus standard (the low energy standard I happen to know about). They are opting to build to truly low energy standards not because of any leadership from DCLG, but because they think it’s a good idea for users/purchasers, and it is possible to make it stack up financially, especially after the first one or two builds have been completed.

They don’t have any special trick, other than the right attitude. If they can make it work financially, then so can the big housebuilders. Perhaps the big housebuilders don’t want to change their ways, perhaps because their business model is based on shoddy workmanship. But the Zero Carbon Hub has told us this has to change anyway, to reduce the performance gap.

If the big firms adopted very low energy design, the marginal cost would fall considerably, as components would drop in price. And of course if all housebuilders were under the same obligation, then there would be no competitive disadvantage. (Your impact assessment cites a theoretical disadvantage versus older homes, but your own research suggest this is a diminishing effect, given that old homes are cold and/or expensive to run until they have had money spent on them, and I mean proper money, not just a Green Deal’s worth.)

I’m not saying this could happen overnight – it would of course take some time to build the expertise. But in what way is this not a desirable goal? How would using less energy not be more desirable than simply wasting energy (by building worse buildings than you could do), and getting someone else to produce some more low-carbon energy somewhere else – or getting them to save some energy that they should be saving anyway?

Given that ultra low energy homes (and buildings of all kinds) are desirable, feasible, affordable and indeed necessary, there isn’t any excuse for not starting out now on a clear path to bring all new homes to a proper truly low energy standard, delivered via the fabric, so it’s built in.  Zero Carbon and allowable solutions are by contrast an unforgiveable diversion up a blind alley.”

Can Passivhaus teach the policymakers to love the occupant?

Ventilation was much in my mind as I dipped in and out of conversations and seminars at Ecobuild this week. And I began to notice a disturbing tendency for airtightness measures and ventilation to be discussed quite separately, with the costs and benefits of each addressed almost as though the two were unrelated.

Again and again, ventilation appeared to be an afterthought, or a problem, instead of an integral part of the assessment of building performance. Several people also lamented that  “well, you can get draft proofing done on a Green Deal, but ventilation doesn’t meet the golden rule, so who will pay for it? – it can’t be funded”. And alarmingly, this dangerous split seems to be reflected in the very structure of the Green Deal.[1]

This strikes me as rather like saying “you can get this operation that you need, but there is no money to sew you up afterwards”.

Ventilation seemed almost to be resented, an ‘obstacle’ in the way of deeper carbon cuts, limiting what could be achieved. All that fresh air spoils the building performance, it seems.

This put me in mind of a similar flavour you find in discussions about ‘comfort taking’. Once again, the pesky needs of the occupants are getting in the way of the true goal of carbon cutting. Thus in its Green Deal Impact Assessment  DECC complained that “comfort taking” leads to “underachievement in real-world energy savings”.[2] Is it really an “underachievement” to make someone’s house more comfortable?

In both these instances, there is a not-so-hidden subtext that the base animal needs of building occupants are a real hindrance to the low-energy, zero carbon perfection we are seeking. And in a way, you can see how if your job is to achieve these goals, a building with no occupiers would solve a lot of your problems.

So it might be unexpected in a way, that it takes Passivhaus, possibly the most shamelessly geeky and science-based standard of them all, to be the one that not only embraces the occupant, but actually starts from the occupant perspective. My understanding of Passivhaus design is it is built from the premise that occupants want comfortable, healthy buildings that are cheap to run. And yet, somehow, it looks as though Passivhaus manages to deliver the lowest energy and (I think you could easily argue) lowest emissions buildings of the lot of them.

Which is why (or at least one of the reasons why), as I remarked on Twitter this morning, I found that Passivhaus crept into my mind quite often, when I was pondering my uneasiness with what was being said outside the Passivhaus sessions. I think the Passivhaus lot are on to something.



[1]  I was told that for post 1919 buildings there is not anything in the Green Deal that requires the advisors to assess ventilation, even when they recommend draftproofing. There are especially serious concerns about the mass-scale installation of solid wall insulation, where the installer alone is responsible for the ventilation strategy, with no back-stop liability resting with a Green Deal provider. This is an issue that needs more than a blog to tackle – hopefully I will get the chance to come back to this soon.

[2] DECC June 2012 Green Deal Impact Assessment