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Last edited 20 Oct 2023
Aaron Gillich, Professor of Building Decarbonisation and Director of the BSRIA LSBU Net Zero Building Centre
 Introducing Aaron Gillich our Guest Editor
Aaron is Professor of Building Decarbonisation and Director of the BSRIA LSBU Net Zero Building Centre, a joint venture between BSRIA and LSBU with the aim of accelerating decarbonisation in the built environment. We spent time catching up on the catch-up that is needed to understand, share, and accelerate our path to net zero, its link to indoor environmental quality, infrastructure changes of the past, and historical fabric.
The main article I have chosen is about the links between air quality and net zero. Often net zero is seen as something that comes on top of the other considerations we have but issues like limiting mould and other pollutants, reducing overheating, and addressing fuel poverty are really all part of the same challenge. It is ultimately about making buildings that are fit for purpose and fit for the future. Retrofitting the built environment to a net zero standard is an opportunity to address quality issues we should have fixed long ago.
We often hear more about the costs of net zero than we do about the benefits. Net zero will be a massive air quality upgrade by removing fossil fuel combustion from our neighbourhoods. BSRIA have a global reputation for their expertise on air quality monitoring and research and so it is wonderful to see them championing the issue through their Air Quality Hub and making it a centrepiece for this year’s BSRIA Briefing.
Another issue we see in the news a lot lately is slowing down net zero action to ease the financial burden. The idea behind this is that action later will be cheaper than action now. Most of our climate policy is highly dependent on the idea of technological silver bullets saving us from really hard decisions.
This IEA report highlights that we don’t need to wait for silver bullets. They argue that 85% of the technology needed to halve emissions this decade is already on the market. We have the technology and our focus for innovation and research should be on how to deploy them at scale. This means that it’s in our hands as building professionals and we should be accelerating net zero, not slowing down.
 Background, activities and interests in buildings
My research interests are centred on the UK energy trilemma of delivering a low cost, low carbon, secure energy system. In particular, I have focussed on the field of low carbon heat and the intersection of technical and policy challenges in meeting the UK’s 2050 carbon targets.
I have worked in industry, government, and academia. I was seconded to DESNEZ (then BEIS) to the Energy Transformation Directorate, supporting and developing technical research to inform policy design. I have worked on a wide range of research and demonstration projects in the areas of low carbon heating, retrofit, and policy.
I’ve essentially been curious about how we create practical solutions that work for individual buildings, and then how we find ways to replicate those solutions at scale. A lot of my focus lately is on the end of gas for heating in the built environment. Gas has become so deeply embedded in our society that in many ways it is our greatest technical and policy challenge in meeting our climate goals.
For the past three years I’ve been Director of the Net Zero Building Centre, which is a joint venture between BSRIA and LSBU aimed at accelerating decarbonisation in the built environment. BSRIA and LSBU are tremendously impactful in the building sector and it’s wonderful that they’ve put the imperative of net zero at the heart of their research agendas.
 Defining what we really need to mean by zero
I think there is still a lack of knowledge in terms of people's awareness as to what net zero really means, on a couple of different levels. For the built environment, net zero means zero not net. There are almost no scenarios that assume offsets or clever accounting will be used for the built environment. So that's the first thing that people should have in the back of their minds, the offsets will be needed for harder to treat sectors. I know zero carbon buildings aren’t easy, but we need to be getting fossil fuels out of the process completely and as rapidly as possible, not hiding behind the ‘net’ part of net zero.
 Defining how quickly we mean
The next thing is that all the scenarios that get to net zero by 2050 require half the work to be done by 2030. I think many still feel we can park hard decisions, or slow down, certainly the last few months in the political arena suggest no sense of real urgency. We are in a position now where every decision counts. Every decision on every project either puts us closer to half by 2030 or further away. A very simple example is that we are still putting gas into many buildings, for which there really is no excuse in 2023. There are design options available, I don't mean to say it's easy, it's not easy. That’s why the default goes back to gas because it is still an easier option. So though there are challenges to overcome to avoid putting gas in a building but every time we fail to overcome those challenges, we are just creating one more building that will need to be retrofitted and will continue to emit carbon in the meantime. Any new build today should be net zero ready without the need for retrofit. If we’re knowingly adding retrofit projects, we’re just moving the problem down the line, and that lack of urgency is a real misunderstanding of the problem.
 What is the value in sharing knowledge across disciplines and institutions? What are the main barriers to sharing and applying knowledge?
 Waiting for what?
The area where knowledge is I think missing or misled is this wait and see attitude. The belief that tomorrow's solutions will be easier and more cost effective than solutions we already have available today. If you look at the technologies available over the time span needed to take these steps, the table is already set, in terms of the list of the scalable and viable options. So, it is distressing when people put hydrogen on the same footing as other options for decarbonising heat, the fact is you can't go and buy a hydrogen boiler right now. And if you want to have the appropriate reduced emissions by 2030, hydrogen simply won't exist in any meaningful way by then, there is a set menu of options ready. IEA looked at these existing technological options and confirmed that to get to those emissions goals of 2030, 85% of the technology already exists. This is a fundamental bit of knowledge transfer that we need to get across to the industry as quickly as possible in everything we to do from here to 2030, we have the tools.
From the sort of tradesman to the to the government, the trickiest thing is sharing that knowledge. I think we have exhausted the low hanging fruit and easy wins that we can achieve within individual silos. The hard stuff is cross disciplinary, across institutions and doing so requires a degree of collaboration. We often like to talk about collaboration across these boundaries, but we aren't perhaps quite so good at doing it in practice. We need to get a lot better at sharing, talking, working with each other - and quickly.
 A national conversation and national collaboration
When you look at the scale of the transformation we’re undertaking, it’s not an exaggeration to say it's nothing short of a national conversation. These kinds of fundamental infrastructure changes have happened, roughly every fifty years. 100 years ago, the issue was building the electrical grid, which would not have been possible without that national conversation. Everyone’s lives fundamentally changed before and after electricity and we needed to talk to each other about what it would mean for us. What choices we needed to make.
Then it was a very similar conversation about 50 years later when they built the gas grid. We went from fireplaces or coal burners to central heating nationwide in about ten years. It required a national conversation about what it would mean for each of us.
It is significant and it affects everybody, from the people building the pilots, people running trucks and cables down the street to the person who has to plug in something for the very first time. The national conversation meant, how does my job intersect with other jobs, you were a plumber? You were a gas engineer? Now there’s a new trade called a boiler engineer. The nature of a lot of jobs changed. How we used our homes changed. And it happened at scale very quickly, and now it is going to happen again with the net zero transformation.
Right now, we have three different energy industries serving three different sectors. Oil for transportation, gas for heating, and electricity for buildings. All of these are about to converge into a net zero electrical grid. All of this is going to be sharing the same infrastructure and it's going to fundamentally change our built environment, in the same way that building an electrical grid and plugging something in for the first time, or how the gas grid changed things. So, it's this scale of change that we're experiencing, that we're in the midst of, you can't have that without a national scale of conversation about what it means for everyone. What’s going to change, and what choices do we need to make.
 Diversity in solutions
It is frustrating because heat pumps, I think have a bad reputation in this country and undeservedly. It is a reputation born really from half a century of basically a ubiquity of gas systems, in a way that effectively drowned out other voices in the conversation, more so here than in other European countries. Many other countries, going through a version of this transition are starting from a more diversified heating solutions mix than in the UK. The opposition from the gas and fossil fuels industries has done such an effective job of muddying the water around heat pumps. It's strange to me the degree to which heat pumps are still seen as novel in the UK, and it is used as an argument against them. Many other countries, for example Finland started using heat pumps over 20 years ago. Most of the barriers we still see to heat pumps were solved one by one a while ago.
I think talking about how we end gas and replace it with something else is important. It’s a complicated mix of national level policy and individual choice. We need the big stuff in place, like a green grid and cost-effective options, but ultimately a lot of the transition will depend on individual consumer choices. When will each of us choose to pay our last gas bill?
The IEA net zero paper speaks to this too. Only a small fraction of net zero savings will come from upstream implementation of technical fixes, like swapping coal for wind etc., those were relatively simple and low hanging fruit. What will remain now is technology enabled individual choices, dependent on end user behaviour, choosing to switch car to electric or use public transport, changing to a heat pump etc. This again will require collaboration and communication, it’s not like flicking a switch that then sort of trickles down and changes the economy, it takes a more concerted and systematic approach.
 Market transformation processes
The policy framework behind this is called market transformation, and it’s actually a really well understood process that we’ve done over and over again. The trouble is now we seem to be forgetting all those lessons when it comes to net zero.
A simple example of market transformation is white goods and electronics. You start with some research and development, create a new more efficient product. Then policy makers use price-based mechanisms to drive early adopters. When you get enough traction you can reduce the rebates, sometimes you have a publicly supported financing option to help the early majority. Then as you get enough market penetration, you’re high enough on the curve that you can use regulations to eliminate the poorer performing options from the marketplace. The market will be mature enough that it can offer competitive options that meet the regulatory minimums without widespread subsidies.
So that package of policy measures from R&D and innovation support, to grants, through financing, and finally regulations. You use different combinations, sometimes they overlap a bit, but the principle is very well established and mostly follows this formula.
The biggest difference between white goods and more complex markets like heating goes back to that national conversation idea. Whenever you are transforming a complex market with lots of moving parts there’s always an information campaign, training, communications, and things like that alongside it. If you’re just trying to go from an F to an A rated fridge the supply chain can kind of, take care of that themselves, they don’t need specialist support for training, but heating is more complicated.
The ‘big switch’ to gas is my favourite example of this. When they combined gas fitting and plumbing into a new trade for boiler installations they had a massive training campaign, they didn’t just leave the market to figure that out itself.
The thing is, you have to have the policies all working together over about a decade or so. You don’t just have individual pieces in fits and starts, that’s what we’ve been doing wrong this time with net zero.
We have a £7,500 rebate for heat pumps, and that’s great. From a policy perspective that’s really cost effective and great for driving the early adopters. The trouble is we wanted the early adopters a decade ago. But if you remember a decade ago, they were trying the Green Deal, which is one of those more complicated financing mechanisms you can only use once you’ve got the early adopters on board and the market is more ready to run with it.
Before the Green Deal we were insulating a million homes a year. But then the support stopped. And we didn’t really replace with anything at that scale. So, we had fits and starts, and policies out of sequence and no real market transformation strategy. By now every single home in the country should be insulated and heat pump ready. If we’d kept going at the pace, we were on 10 years ago, the goal of 600,000 heat pumps by 2028 would seem quite achievable. So yes, it does sometimes feel we have lost ten years in my opinion.
Well, I have only recently been introduced really, through our work with BSRIA. So, no I don’t have an account yet, or perhaps more accurately our Net Zero Buildings centre doesn’t, but I think it would make a great communication channel for the work we are doing and as we have been discussing cross discipline, accessible links of communication really are crucial to getting this information and knowledge out there.
I haven’t but I will be now! ...
 Do you have any favourite themes relating to buildings and construction, particular eras of construction, styles, technical areas or any favourite building that springs to mind?
I think an important theme is about the links between net zero and indoor environmental quality. And I’m so glad that BSRIA is focusing so much on that this year, including making it the theme of their BSRIA Briefing Event in November.
Historically building services didn't really exist, prior to the 20th c it was all passive and just clever architecture and engineering. Then suddenly in the 20th c an explosion of innovation, around building services tech and access to cheap energy made things achievable, so comfort expectations took off. Even something like central heating is taken for granted but in building terms it’s relatively new tech, I mean a lot of people alive today grew up in homes before central heating was common. Tech and cheap fuel enabled rising standards of comfort.
The 21st century is going to be about keeping those comfort standards but without the carbon, about revisiting passive systems that worked before and layering these with ideas and innovations where technology can add value but in ways to do so without throwing energy at the problem. I mean the simplest way to make a building zero carbon is to just turn everything off, that's hardly not the point. We will adapt our comfort perhaps through social norms and how to make buildings work more efficiently, but you add up every IEQ problem we have in buildings today and net zero should be seen as a solution for them not a compromise to them. Meeting carbon standards is a part of the answer as to how we fix these problems in our buildings, that we should have fixed before.
This again links back to the national conversation and the market transformation ideas they used in the ‘Big Switch’ to gas. When gas and central heating came along, they sold it with a national campaign called ‘guaranteed warmth’, such a simple, beautiful two-word sales pitch. One that had a huge impact, but if we look at the built environment many were still left behind. Every winter we still have people dying due to cold homes. This isn’t just a deprivation issue, it’s specifically attributed to poor quality homes, and there is absolutely no excuse for this in a modern economy.
We were sold gas on this promise of guaranteed warmth, and it was true for many, but a lot of our buildings are still very cold. And then on the flip side a lot of our buildings are not fit for purpose in dealing with rising temperatures in the summer either. So, we are looking at increases of heat related deaths. There is also the tragic death of Awaab Ishak due to long term exposure to mould. Mould is unfortunately a relatively common issue in UK homes, and it’s not simply because we aren’t ventilating properly, it’s wrong to just attribute it to user behaviour. These kinds of indoor environmental quality problems just should not be an issue in 2023. So, I know I’m bundling a few issues here, underheating, overheating, mould, discomfort. They are separate issues, but there’s a Venn diagram of solutions that helps them all, it’s ultimately about improving building quality.
These things can be fixed with retrofitting and perhaps like ‘guaranteed warmth’ it is a pathway to a lot of hearts and minds that I don't think we are fully engaging with. That national conversation should be about net zero retrofits as a way of addressing many of these long-standing persistent problems in our building stock. To see zero carbon as that multifaceted solution not some kind of sacrifice that's being thrust upon us, rather a way to make buildings that are fit for purpose and for the future.
I grew up in Canada as you can probably tell from the accent, we moved here 15 years ago, and it's always been my dream to live in an old British cottage. I just love this style of architecture the sort of quality of homes, the character the heritage values. The idea of living in a new build never appealed to me and we finally just moved in last year to an Edwardian era Arts and Crafts style cottage. I guess maybe I’m drawn to the historic or heritage buildings I didn’t see a lot of in Canada.
I love the aesthetic and charm of homes and buildings like this, but I also think they are the paragon case for net zero in the UK. We must find a way to make homes like this fit for net zero without losing the quality and character that makes them what they are, that sort of richness. I'm now as a result in the process of doing that to our new home, so I'll let you know how we are doing in a year.
But I think it is one of the challenges of the UK, I'm fascinated by historic or heritage buildings. When you walk around old buildings and look, you don't see the cables, the pipes, these were after all retrofit modern conveniences that we now take for granted. The original building certainly wasn't built with any of those things, it was completely designed without plumbing, electricity, gas, or anything but we have found ways to fold those into heritage homes and buildings over the years as our standard of life has evolved and we need to do the same thing now with net zero.
That idea of comfort without carbon also means keeping the heritage quality of those buildings to treat this with the same sensitivity but the same sort of degree of importance. These buildings would have long since become unusable if we hadn’t retrofitted them with electricity, heating, and plumbing, and net zero is no different.
 Would you like to nominate someone for the guest editor slot ? and please do give us a little feedback on the experience of being our guest editor.
Yes two people, Jaya Gajparia and Samuel Johnson-Schlee in the social sciences who look at how we use our homes and how that will change with the climate.
I’ve greatly enjoyed being a guest editor for Designing Buildings. I think it’s a very important site that offers timely information in an accessible way. It's an excellent source that I share with my students and I was grateful to be invited to contribute.
- Air quality hub.
- BSRIA Briefing 2023. Cleaner Air, Better Tomorrow
- BSRIA Occupant Wellbeing survey BOW.
- BSRIA publish net zero guide.
- BSRIA Thermal comfort TG22/2023 update.
- Cultivating Cleaner Air with BSRIA.
- Industry responds to Prime Ministers Net Zero policy announcement..
- Net Zero: Practical Pathway Programme.
- Net zero building centre with BSRIA and LSBU.
- The Global Context for Net Zero NZG 3/2023.
- The LSBU and BSRIA Net zero building centre, topic guide Net Zero Carbon Buildings.
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