The Retrofit Challenge

City of York Green Councillor and Executive Member for Housing and Safer Neighbourhoods, Denise Craghill, explains the thinking behind the council’s retrofit plans she approved last week. She says:

“This £1m investment in improved energy efficiency in the city’s council housing stock is the first step in our commitment to tackle the retrofit challenge in York in the most effective and strategic way possible. As and when we move out of the Covid emergency, the Climate Emergency will still be here and is the biggest challenge to our future security that we face on a local and global scale.

The need for large scale retrofit

80% of the housing stock that we will have in 2050 has already been built, so to have an impact on the third of local climate emissions that come from housing we will need very significant levels of investment in retrofitting existing properties.

Most of our existing housing stock – council and social housing, private rented and owner-occupied needs a lot of work to make it as energy efficient as it could be. The technical knowledge and expertise to do this already exists but in this country so far we have a very limited track record of doing this in practice and at any scale. We need to develop and share knowledge, skills and experience amongst local builders and contractors, project managers, quality assurers and supply chains.

Reducing the demand for energy

The Passivhaus techniques the council will be using for our new build housing programme deliver the highest levels of thermal efficiency, which means that buildings are warm and comfortable to live in and the need to use energy for heating or cooling the building is kept very low. This means that climate emissions, the demand on the national energy supply system and individual energy bills are kept very low.

The ‘very low’ bit is really important here – especially in relation to energy demand. As we stop using fossil fuels altogether (which we have to in order to tackle the Climate Emergency – for example, Government policy is that no more gas powered boilers will be installed by 2025) – we can only make a future energy system balance up by reducing the overall amount of energy that we need to use in order to live well. A Passivhaus type of approach to all buildings gives us that opportunity. It also gives us the opportunity to provide comfortable to live in buildings with very low energy bills for occupants – a double ‘win’ that has to make a lot of sense if we can deliver it.


One big challenge of course is the cost, particularly for retrofitting older buildings that weren’t built with energy efficiency in mind. ENerPHit is the retrofit equivalent of Passivhaus. It also ensures an approach to the building that puts ‘thermal efficiency’ first and makes emissions, energy use and energy bills as low as possible. It ensures that we don’t just change the boiler, stick some solar panels on the roof and leave the new heating system losing so much heat through the walls, floor and roof that the occupant is still effectively paying to heat up the outdoors!

The costs of doing this can certainly seem daunting – but then we do have to start somewhere – or we get nowhere! As with anything else, the early costs of an approach that hasn’t been implemented so far at scale are going to be higher than they will be when we have scaled up and made retrofit part of our ‘new normal’ – with the potential to create many jobs along the way.

The Energy Accelerator Pilot Project that I approved last week will make that start by retrofitting up to 30 council properties to ‘EPC C’ (based on the Energy Performance Certificate rating that is currently a legal requirement for private landlords and house sales) and up to 8 council properties up to the far more ambitious and more thermally efficient ENerPHit standards. The £1m project will be supported by experts from the regionally based Leeds Energy Accelerator and will also use an ENerPHit architect.

It is estimated that the 8 homes to be retrofitted up to the EnerPHit standard could cost up to £68,000 per home. As a result, each household will save an estimated £440/year on energy bills, reduce their carbon emissions by an estimated 1.9 tonnes of CO2 per year and end up with a warmer and more comfortable home. 30 additional houses will be improved to an EPC C rating at an estimated cost of £15,000 per household, resulting in approximate savings of £260 on energy costs, and 1.1 tonnes of CO2 per year.

Additionally, the householders who participate in the programme will be helping to lead the way in developing our local retrofit programme and helping us to learn how to scale it up to more houses in future, to benefit more people, reach our climate change goals and to identify future economies of scale which may bring future costs down. Again, if we don’t make a start on this, we certainly won’t get anywhere!

Some final thoughts on costs

£68,000 may sound like a lot – but it is certainly a lot less than the cost of a new house – yet the finished properties will be a bit like getting a new house. It may sound like a lot but let’s compare it for a moment with the cost of resurfacing a road or a subsidised bus journey. Resurfacing a very short stretch of side road in my ward is going to cost £35,000. The council’s annual budget for highways resurfacing is over £7million pounds and is never enough. The council subsidises bus services each year to the tune of nearly £650,000 and some individual journeys, which enable older and isolated people to get out and about cost quite a lot. Some of these things are expensive but as a Green I am in favour of investing public money in the public good – subsidising public transport and ensuring that our city roads are of a decent standard to facilitate their use by many different road users. I’m also in favour of investing in highly sustainable and energy efficient housing as a public good, which will help us reach our climate targets, reduce fuel poverty and also support new local skills and provide new jobs in these difficult times. As Greens we believe that housing is a public good that we should invest in for the future.

The £1m budget that we have available for this project is not going to come close to retrofitting the 7,500 council properties that we have in the city (not to mention the 80-90,000 homes we have across all tenures). This fact will stay the same whether we use this money for 30 – 40 homes or for 30 – 60 homes. The aim of this project is to use this money strategically to make the greatest possible difference to our capacity to draw in further funding and to scale up in future.

Strategy and scaling up

The overall approach will be as far as possible to maximise the thermal efficiency of buildings which will ensure they are comfortable to live in and have very low carbon emissions and very low energy demand far in to the future. To this end the project will also develop a ‘road-map’ from EPC ‘C’ up to ENerPHit standards. This range of approaches will mean that we can learn as much as possible about how to do retrofit properties as well as possible in York – developing our approaches to design, contractor training, project management and supply chains.

The whole focus of the project will be on how we can identify ways to scale up, retrofit more council properties, reduce carbon emissions and energy demand in the city and open up the prospect of warmer, more comfortable homes and very low energy bills to more of our tenants who are currently living in fuel poverty.

What will this mean for tenants taking part in the project?

The next phase of the project will involve a lot engagement with tenants to explain the aims of the project, the advantages for them if they decide to participate and the challenges of both approaches to retrofit. In both cases tenants will need to be prepared for some disruption. For the whole house EnerPHit standard retrofit this will be for a longer period of time. Contrary to some reporting, tenants taking part in the EnerPHit approach will need to move out for around 2 -3 weeks (and this will be funded by the council) – NOT the 6 months that has been mentioned. The works on their house may last for up to 6 months but they will be able to stay in the house for most of this time.

Retrofit for other tenures

Obviously this project and the scaled up work that we hope will follow from it, only applies to council housing. The Private Rented Sector accounts for around 17 -20% of York’s housing stock whilst owner occupiers account for around 65%. The council has recently been awarded some funding to work with landlords to improve the energy efficiency of some of our very worst performing private rented housing stock. At the same time we are very aware that owner occupiers hold the key to a large part of the retrofit challenge and we are looking at ways we can better support them, whilst also working with community based retrofit initiatives. The more work we do on all of this, the more we will identify synergies between different sectors and be able to share learning and approaches to retrofit both within the council, with our partners and across the city.

Retrofit Update 20th July 2020

Since this article was posted the decision described above was ‘called-in’ for review (a few days later) under the council’s call-in procedures by the Labour and Conservative groups, on the basis that the spend per property for the 8 ENerPHit homes seems too high and not cost effective. It then became clear that there were also some procedural issues with the decision paper. The procedural issues meant that the council’s senior legal officer decided to revoke the decision and request officers to rewrite the paper and bring it back to a new decision session. This is likely to happen in August or September. This doesn’t necessarily mean that the options for action on retrofit will change, simply that the evidence to support the actions should be strengthened and set out in the paper in more detail, whilst the procedural omissions will be corrected.

Cllr Denise Craghill says:

‘It is disappointing that we will have to take a bit more time before we can get on with making on start on this very important project. However, it is important that the decision is made correctly and with a strong evidence base. I can understand why at first sight people might question the difference in costs involved in these two approaches. However, as with anything else, the cost varies depending on exactly what is done and what the outcomes are that we are looking to deliver.

The work to be done to bring some of our worst properties (in terms of thermal efficiency) up to EPC C and estimated in the report at £15,000 per property will make some valuable improvements to the comfort levels inside the property and will make some savings on energy bills and CO2 emissions. The level of CO2 emissions saved may be reduced to some extent by the householders taking advantage of improved comfort for less cost.

What this won’t do on its own, however, is tackle the challenge of the deep retrofit that we need to develop at scale in order to reduce energy demand from housing to very low levels and tackle climate change. The £68k per property estimate for the ENerPHit approach to retrofit, which will maximise thermal efficiency, is an industry average for this sort of work.

It will enable us to develop project management techniques for this type of retrofit, tackle the challenges of skills development and training for contractors, create local supply chains, work with residents on how to manage the retrofit process and how to monitor and evaluate living in the homes afterwards. It will also put us in the best position to draw in further funding for scaling up when it becomes available.

I am disappointed that whilst Labour is quite rightly calling for a ‘bold approach’ and ‘strategic ambition’ to tackle the Climate Emergency, they don’t seem to understand how this applies to the challenge of making our existing housing stock fit for a zero carbon future.”

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