When I was studying to be an architect in 1990s Liverpool our design tutors gave us a project. We were to choose a method of generating renewable energy by the Mersey, and then design a ‘theme park’ ride that would be powered by this energy.
Now it’s worth remembering that as a design project in an architecture school, this was a vehicle for learning, and did not include a cost element. Thinking about it, only one project I ever did in 7 years of academic study to be an architect involved the monetary cost of anything.
Well, I couldn’t get with the brief. I just didn’t accept that this was a reasonable thing to do, in a recession, in a northern city struggling with unemployment and social tension. There were people living in the same street as me who couldn’t afford to heat their houses. But mostly, I didn’t agree that one should create energy simply to waste it on a theme park. It felt so much like the Liverpool Garden Festival debacle all over again but with Greenwash. Why not save energy instead?
Apparently, saving energy was not sexy.
Later we discovered that the purpose of this project was to generate ideas for the tutors to use to enter a competition in a national architecture journal about renewable energy. I kid you not.
Anyway, what has that 19 year old story got to do with today’s debates on sustainable housing?
Points
In those days energy standards for homes were incredibly lax by today’s standards. These days it’s all about points, and points mean prizes.
The Code for Sustainable Homes which is the compulsory standard by which all housing must be measured in the UK. Level 3 of the Code is compulsory for Grant Funded Housing now and will be for all housing next year. The Code involves calculations designed to reduce the carbon emissions of the construction and operation of housing. It is based around the concept that carbon emissions are what are causing global warming, so by reducing the huge carbon footprint of new build housing we can reduce our CO2 emissions and thereby save the planet.
One of the ways in which you get points in your quest to reach higher levels of the code is to generate renewable energy on site. You can take it out of the sunshine, fish it out of the ground or catch it from the wind. You can even grow it and burn wood chip in boilers. The homes are better insulated too, but you get points for making ‘green energy’, and at higher levels it is almost mandatory.
These days, sustainable housing isn’t just about points though, its also about money.
Money
Unlike my university project, meeting the code for sustainable homes has to have a cost implication, and as architects our objective must be to deliver a project that meets all the needs of the client, including cost criteria.
In the short term, open housing market, and for those whom capital (construction) cost is the only issue, this means choosing a technology whose first and sometimes only objective is to meet the needs of the Code as cheaply as is possible.
But if you are a Housing Association or a Residential Property Investor, the homes you build also have a maintenance cost to consider, which may affect your choice of technology.
And as a property owner with a long term interest in your property, you may also want to provide homes which you or your tenants will find cheaper to heat. Energy costs money, even if you don’t have to dig coal out of the ground to get it. So why not save energy instead?
This is why Barefoot & Gilles developed the GreenGauge Homes approach to affordable housing, to look at the whole picture and take all the clients needs into account. If this means assessing what training tenants need to live in the houses (and choosing technology to minimize it), how easy they are to look after (and choosing approaches which made it easier), what their energy bills might be (and designing to help reduce bills), then so be it. The University of East Anglia are doing the monitoring and lessons learned about both tenant attitudes and real energy bills are moulding the progression of future projects. A bit of joined up thinking at the beginning will save so much heartache (and cost) which is going to face our Code rated homes in years to come.
What has come to mind for me, is that like my story about the theme park powered by renewable energy generation, the Code isn’t quite getting it. House builders don’t have to think about the future energy use of their Code 3 & 4 houses, indeed they are installing technology which makes ‘free’ energy and perpetuates the idea that the amount of energy one uses is not the issue.
Furthermore all this new and largely unfamiliar technology is making homes more complex, more prone to maintenance problems, more difficult for ordinary people to live in.
One thing which has stayed the same though. Making energy on site is still sexy, but that is really all it is. It might be sexy but it’s not clever.
This is where PassivHaus comes in.
Energy
PassivHaus is an approach developed in Germany. The basic premise is to reduce the energy use of a home to a minimum, firstly by ‘super insulating’, and then by reducing heat lost by air loss. The result is homes which use a tiny amount of energy, because all the energy in the bodies of the occupants, the equipment and lighting in the home, contributes towards heating it and is not lost through exhaust air or poor insulation.
Now I’m not saying that PassivHaus is the answer. The homes have to be airtight, something which normal British housing just is not. Airtightness is such an issue that it bears upon the construction process so much that there is debate about whether our industry has the capability to build these homes in volume. There are also voices raised about the wisdom of such an air controlled home, about stuffiness and practicality.
Perhaps the practical implementation of a PassivHaus type of approach would be just as challenging as the Code is turning out to be for the UK. Maybe we will have to find a reasonable compromise.
Nevertheless, the idea of a home built to save, conserve and reuse energy just seems to be a much more sensible starting point. Don’t you agree?
Su, great article. I would comment that the Carbon Hubs definition of Zero Carbon for the UK uses PassivHaus as an inspirational standard. (as reported on their roadshow and documentation)
I see three challenges for PassivHaus – on construction quality, on end users & lifestyle and on addressing existing homes and the whole commercial industrial and public building stock.
I will post in more detail over on my isite blog at http://www.fairsnape.wordpress.com
Yes I agree! Very heartening to hear support for a rational and more cost effective approach to energy efficiency.
The airtightness issue that you flag up is worthy of more discussion. Leakyness may be ‘useful’ in reducing condensation and stuffiness in some poorly vented buildings but has no benefit in buildings with proper controlled ventilation, eg MEV or MVHR. Leaky buildings are cold and draughty and warm moist air leaking into the insulation can cause structural damage. However people continue to confuse uncontrolled leakyness with proper ventilation.
Ironically Passivhaus certification requires a maximum leakage of 0.6 ac/h at 50 Pa because airtightness is actually a very cost effective way to save energy. However it requires a step change in design to make such a tight (by UK standards) target routinely achievable.
As with all other aspects of PH, airtightness can’t be bolted on as a contractual requirement but has to be designed in.
The fact that airtighness, building form, orientation, insulation etc are hard or impossible to retrofit is a really good reason for focussing on the core design rather than blowing the budget on toy renewable that could be added later – if they are ever proved to work.
Sorry my comments as long as your post.
Nick
We are building 8 new flats and I really wanted to make it an ecological development, in particular I thought a combination of solar panels, heat pumps, and underfloor heating would result in a magnificent scheme. Sadly the £ didn’t work out. There is the goodwill, but not the financial incentive.
I recently came across a Passivhaus project in Kent which was an office built by a developer with experimentation in mind . They had a huge input from German Arcitects with the expertise .
Simplified, The design included large masses of concrete and a single skin of lightweight concrete blocks with at least 300 mm of polystyrene
attached externally as insulation .They also had triple glazed windows as standard and data recorded HVAC to provide optimum summer and winter temperatures . The materials to build it were not particularly green but the claims for the saving on energy / heating bills were amazing .
Does anyone know where there have been studies to compare build costs between traditionally built offices with a Passivhaus say in Germany where they are light years ahead with this technology.
I just have an amateur interest in this and all sustainable building .
I also have an interest in Rammed earth building and low tech solutions such as at CAT and Pines calix Dover .
Sadly all these ideas do in the end boil down to initial build cost which is what prevents more projects from proceeding . the secret is surely to persuade everyone that the long term investment is wortyh it .
I think you’ve hit on a very fundamental issue at the heart of modern construction on a residential level. Generally speaking, when considering single properties there are more important considerations than just the value added quality of any additional energy related work; namely any initial launch costs, the longevity of the system used and the level of maintenance.
What we as architects need to be focusing on is promoting concepts that provide a more holistic answer to the problem of reducing the carbon footprint (not even taking into account whether this is indeed the issue to begin with) of homes.
Whilst I agree with your new starting point, I disagree with your assessment of what can and cannot be done with the production of renewable energy. What we must aim to do is create a plus energy society, one where the flow of energy is high enough, and constant enough that is abundant and cheap.
Great article Su, gonna send you some retweet love!
I think the Passivhaus standard can be a key component in acheiving the coveted Zero Carbon Home, as it utilises fundamental principles which we all understand, that of energy efficiency, energy conservation. Coupled with use of renewable energy sources, e.g. ground source heat pumps, solar panels, it is felt, such ambitious low energy, low Co2 targets can be reached.
See http://www.energy-measures.com/passivhaus/