Comfy homes, green jobs, zero gas-burning and world leading construction technology - what’s not to love? This question is close to our hearts at Transition Town Brixton. Ever since the early days of TTB activities like Draught Busters and the creation of Brixton Energy, we have seen the importance of insulating homes as part of the transition to a low carbon future. In the past few years, we have started to see that social justice and environmental justice are inseparable.
These are some animations to outline the “technical” case for retrofit. Everything is illustrated using publicly available data and reputable benchmarks. That these data are freely available to us is one of the wonders of life in the UK: thank you to the people who demand data and gather data for the public good.
These animations are all based on true stories so thanks also to everyone who has let me cross their threshold and talk about energy and retrofit over the years. They have shown me that the case for retrofit simply isn’t a complete story without thinking about the:
costs to households of business as usual, including impacts on health
impacts on the environment over the whole lifecycle of a house
impacts of rising energy prices and decarbonisation elsewhere in the system
implications and intersections of tenure, race, class and age. Whether you rent privately, rent from a council or housing association or own – all of this impacts your energy costs, your costs of finance, even the power you have over your boiler and, ultimately, whether you can expect to face the threat of demolition or the promise of retrofit.
Housing Costs: same house, different wealth
Let’s start with something everybody knows about: housing costs.
Housing costs per month: same house, different wealth
A friend told me this story of her neighbours in north London who were renting and paying 5 times in rent what her family was paying on their interest only mortgage – if you are paying a mortgage and things get tight, there is the option to just pay the interest and that cuts your outgoings by about two thirds.
Imagine the Same House but what you pay per month depends on Different Wealth and how your housing has been financed. On the left is the market rent, then your mortgage payments now if you managed to buy and rustle up a £60 to 70k depost. Then we have London Living Rent, Housing Association Rent, Council Rent and, finally, mortgage payments if you managed to buy 10-15 years ago (and that is a conservatively high estimate and does not show the associated increase in wealth because property values have risen).
Heating Costs: same house, different household
Now, let’s think about the heating bills in the Same House but with Different Households.
Heating costs per year: same house, different household
I’ve seen households in identical, neighbouring houses, one with a heating bill 3 times the other. Don’t take my word for it: this is backed up by the Energy Systems Catapult found that varied 5 to 22 hours per day, 15-23degressC, 23-80% of rooms “vulnerable households are not all the same… vary as much as those of other consumers”
Why?
Because it depends on how much you are at home and what you need. I never call this “behaviour” because many of the factors are not “lifestyle choices”, they are “unchosen” like life stage, health status, age, height and weight, work schedule, household composition, whether you have gas or electric heating, whether your tenure allows you control over the fabric and systems in your home… So, the drivers of these differences do not map directly to income – in fact, the times when you might need the most energy, are the times when your income might be lowest (maternity leave, retirement, long Covid).
And what about health?
You can imagine that, given cold temperatures have a direct impact on health and under-heating can exacerbate damp, condensation, mould which also impact health. In fact, there is no need to imagine - there is an extraordinary amount of evidence linking poor health outcomes and housing and heating costs (social and the private rental sector). It’s even worse than this because as NICE said in 2005 “It is likely that the causal link between housing and health works in both directions, with housing affecting an individual’s health and health also affecting an individual’s housing opportunities.” [1]
… I could go on – without even getting to income inequality, you could overlay council tax, NI contributions, travel costs, lack of land taxation… And then you could shift the focus from single homes to housing as a whole, add in demographic data on class and race, environmental data on air quality and you would see the landscape of injustice that is built in to housing and other infrastructures. And although the costs of the resulting problems are paid by all of us, one way or another in bills or taxes, it seems the less you have, the more you pay… But the points to take away here are:
Housing costs are still much higher than energy costs in London (but energy costs are similar across the country and winters are harsher elsewhere so this ratio is not across the country)
All this variation in bills is why we have Energy Performance Certificates (EPCs) to compare houses without the differences between households interfering
EPCs are required but obviously because of the fundamentals I’ve just shown you, energy performance is not a key driver of house prices or rents at the moment
Health is not just about indoor conditions but also outdoor… In a 2019 survey, 47% of people were not aware that domestic boilers have an impact on the climate and I bet the same is true for their contribution to air pollution (the National Atmospheric Emissions Inventory - a thing of beauty - shows this is a 10% contribution for PM2.5s). See this post on the extra household and societal costs of energy inefficient housing
Retrofit: same house, same household, different retrofit
So what happens if homes are retrofitted or knocked down to make way for more energy efficient New Build housing? All other things being equal (as per the EPC), bills go down.
Same house, same household, different retrofit
Savings from a “Shallow Retrofit” of basic insulation measures to lofts and cavity walls is taken from the National Energy Efficiency Data (NEED) framework. Even though this is probably an under-estimate, you can see a reduction. In the middle, I’m using the targets set out in two 2019/20 public tenders (GLA Retrofit Accelerator and Social Housing Decarbonisation Fund), the next case uses the LETI new build/EnerPhit passive house retrofit targets. The final example is demolition and new build. I’ll follow on from this blog with more on what these shallow and deep concepts mean in practice.
Am I better off knocking my house down and starting again?
Not if your new house is typical of new housing in the UK! If you demolish a home and get a new house built to the current building regulations, your monetary saving is only a bit better than a shallow retrofit. And that is only if - and it is a big if - the house is built well enough to achieve compliance with building regulations in its real thermal performance.
What if my bills don’t match what the EPC says and/or they don’t seem to have gone down after retrofit?
It is worth mentioning that in terms of the monetary savings you experience as a household from one year to the next: all other things are not equal. The winter weather might be different, your tariff might be different, your life might be different. In fact, there is reverse causality: some things that might make your bills go up are the same things that might cause you to retrofit, like kids leaving home, retirement, extending your house or your family.
If I get rid of my gas boiler, isn’t electricity 4x the price of gas?
Thinking about the bills here has an extra level of complication. Electricity tariffs are currently 4 times gas tariffs so shifting to a zero gas gas future with a “business as usual” heating demand will be crippling for some households in the worst houses.
Bills when you change how heat is delivered
But this is not the whole story…
What I’ve been talking about is the energy you use once a building has been built or the Operational Energy. Emissions come from more than just the energy that buildings use over their lifetime. There is also the energy (and carbon) that go into building, demolition and disposal.
This is a graphic from the fantastic London Energy Transformation Initiative’s Embodied Carbon work. It’s a companion to their Climate Emergency Design Guide.re you can see in pink what is called embodied carbon – the emissions associated with producing the materials, transporting them and building. In yellow, is the operational carbon – the emissions from your boiler and from the power stations that supply electricity and this assumes a life of 60 years.
So when you run the comparison again and include embodied carbon – the picture changes and you can see that, if you rebuild to current build regs, you might as well have not done anything.
Whole Life Carbon (WLC) for different retrofits
How much does this cost?
Well, costs depend on materials, labour, financing and efficiencies of scale (do loads, reduce the cost per unit) and scope (deliver by type, reduce complexity).
Houses – even when they are roughly the same archetype – often need different treatment because they have been modified over time, have asbestos or need a specific fire strategy, so large scale retrofit is less amenable to “industrialisation” by mass-production - instead, we need to think about mass-customization (see this paper on Japanese mass-customization of housing, driven by many unique factors including a land ownership structure that made it harder to make money on land deals and so instead drove innovation into the supply chain - design, fabrication, customer choice.
Just imagine that idea for a minute.
There is 20% VAT to pay on retrofit but only 0-5% on New Build so the balance sheet is already biased…
If you are involved in a struggle over demolition of your housing, the cost data is the hardest to confirm. It is often deemed commercially sensitive and, because data on alternatives to demolitions is not systematically collected and shared, it cannot be checked easily by a curious public.
There is cost analysis out there but sometimes it is:
£ per hous,e for example, the stated ambition in recent public tenders is to reduce the cost of deep retrofit from £85k per home to £55k by packaging up large numbers of houses and developing the capability of contractors and the retrofit supply chain
£ per square metre of internal floor area, for example, LETI’s energy and carbon benchmarking. These are also the units I’ve used to develop scenarios faced by households. Although, this is roughly in proportion to the size of your house, this is not granular enough to apply to your own situation
£ per square metre of the surfaces to be retrofit, for example, the cost per square meter of your windows or walls. A good example of the last one is the Retrofit for the Future: analysis of cost data but these benchmarks shift and adjust with inflation, supply, demand, location and maturity of the technology
Reasons to be cheerful
Retrofitting our housing stock will be a Herculean task but here are some reasons to be cheerful.
Innovation in procurement
There is now a publicly available specification (PAS2035) - to be used in large-scale procurement of retrofit. It defines a retrofit delivery framework (i.e. project management) incorporating learning from builders, households, engineers and architects.
BEIS is about to launch the Social Housing Decarbonisation Fund in autumn 2021 (the demo has been running for 18 months) and the requirements to innovate and deliver real savings are written into these contracts.
The GLA has launched a Deep Retrofit Accelerator tender with demanding energy performance criteria for contractors.
Jobs and skills
Jobs - with skills fit for a better future - will be created by investment in retrofit
The lovely Retrofit Academy has brought together their forensic knowledge of retrofit into a NVQ Level 5 Retrofit Coordinator qualification. The are delivering training through networks of existing energy assessors, architects and engineers. The role of the Retrofit Coordinator is defined in PAS2035 in recognition of the skills gap and the complexity of domestic retrofit
Innovation in finance
Some mortgage lenders desperately want to lend for retrofit to reduce defaults and find a place to send money looking for green investment
Cooperative and Community Energy Financing - Carbon Coop in Manchester has launched a community share offer to support retrofit and Brixton Energy/London Repowering has proven this model for other types of community energy
Industry groups, private sector employees and leaders are declaring a climate emergency and reacting to encourage retrofit over demolition
Architects via RIBA’s #retrofirst campaign which foregrounds the ridiculousness of VAT on retrofit
Engineers via the Royal Academy of Engineering see retrofit and reuse as a key part of decarbonising the construction sector
Built Environment Professionals volunteering via the London Energy Transformation Initiative (LETI) have produced a Climate Emergency Design Guide – arguing for More Ambitious Operational Targets and New Embodied Energy Targets (there are currently none)
Models behind the animations
The assumptions and calculations behind the graphics are here.
[1] Taske et al., ‘Housing and Public Health: A Review of Reviews of Interventions for Improving Health’.