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Retrofitting for the future: Net zero for existing building stock

How crucial is retrofitting to meeting net zero targets? How can the scale and speed required be best achieved? Here are some of the things we learned during our recent webinar.

Steven Matz, Content Specialist, WBEF
29 June 2022

Reuse and recycle

Tina Paillet FRICS is RICS Senior Vice President & CEO of Circotrade. She says, ‘If we are serious about achieving net zero while meeting the need for high performing and affordable build space, retrofitting has a key role to play. The EU alone has set a goal of renovating 35 million buildings by 2030. To realise the full potential of decarbonising the building stock, we need to use more reused, recycled, and low carbon building materials’.

Retrofit can be completely complimentary to the circular economy approach. To make it work, we need to drive its adoption, so as many businesses and projects as possible start using circularity as a core principle. ‘Renovation and material passports are an important initiative providing information on materials used and allowing them to be salvaged and recovered for further use in other buildings. Connecting sellers and buyers at scale to create a viable secondary market is also an essential part of increasing circularity’, adds Tina.

In France, a new thermal regulation, RT2020 (which came into force on 1 January 2022 in respect of residential buildings), has embraced the renovation wave. Regulation RT2020 extends the goals of previous legislation to include the reduction of carbon emissions throughout the lifecycle of a building. ‘This means an ever-decreasing threshold in both embodied and operational carbon, and a regulatory framework that is foreseeable and which will progressively meet the targets that France has set,’ comments Tina.

What does low-carbon heating look like?

‘The vast majority of carbon emitted in the operation of buildings comes from heating systems, which makes designing interventions with that in mind critical,’ says Daniel Newport, Head of Net Zero - UK Policy, Tony Blair Institute for Global Change. ‘But big questions remain as to how we get there,’ he adds.

What does low-carbon heat look like? Is it replacing natural gas with hydrogen, which has a very like-for-like feel to the consumer, but necessitates significant upstream infrastructure investment? Or is it switching to heat pumps, which will increase electricity generation requirements and raise the bar on making buildings energy efficient and on heating distribution systems. ‘Over the next few years, we are going to need really firm decisions on what the roles of these technologies are, because they really do define the challenge for householders and for businesses’, stresses Daniel.

To realise the full potential of decarbonising the building stock, we need to use more reused, recycled, and low carbon building materials

Tina Paillet FRICS
, RICS Senior Vice President & CEO of Circotrade

Improving housing standards

Around 1 in 5 five homes in England fails to meet the Decent Homes Standard (rising to 1 in 4 for private rented homes). Retrofitting to decarbonise provides an ideal opportunity to solve some of the other issues around housing. These include damp homes, independent living, and fuel poverty, says Katie Adnams, Place Innovation Lead, Connected Places Catapult. ‘It also provides a chance to adapt our homes to be more resilient to changes in weather patterns such as extreme heat and increased rainfall’, she adds.

The data gap and retrofit as a service

The UK has a very diverse housing and building stock. ‘That's a real challenge because it means it's hard to scale retrofit if you can't mass produce the same standard components’, says Katie. The diversity of buildings is one innovation challenge. ‘We need to develop individualised products to respond to the diversity of homes, produced using mass production techniques. This needs to take advantage of factory production, without attempting ‘one-size-fits-all’ conformity,’ adds Katie.

Developing the best methods for gathering evidence to ascertain which retrofit interventions work for what homes is another challenge. Smart meter data is a key opportunity to look at this and monitor impacts, though the data can also be used to target homes most in need of retrofitting and those living in fuel poverty. A Connected Places Catapult project with smart meter data looked at this as one of their 'data for good' projects[Please hotlink:]. Some interesting work is being carried out by SMEs in developing data to help social landlords look across their portfolios and improve EPC ratings, says Katie.

Just under two-thirds of housing stock in England are owner-occupied dwellings. ‘Upfront costs, fear of being an early adopter, lack of awareness about standards and an absence of evidence on an individual basis of the benefits are holding back the uptake of retrofitting’, explains Katie. Connected Places Catapult examined 'community retrofit as a service' to look at overcoming these homeowner barriers. They have developed a prototype exploring how to access tailored retrofit options for properties, connect with peers, access grants, and connect to a trusted supply chain. Connected Places Catapult thinks such a service could help evidence and scale demand and monitor the uptake and actual impact of retrofits.  Further information can be found in their report, Integrated Planning for Net Zero.

Solving the financial problem is going to be a big part of the retrofitting solution

Daniel Newport
Head of Net Zero - UK Policy, Tony Blair Institute for Global Change


Energy Systems Catapult have run innovation trials in its Living Labs for heat-as-a-service. Called ‘Heat Plans’, consumers buy hours of guaranteed warmth, rather than units of energy (kWh), which aims to encourage consumers to switch to low-carbon heating. The trials were conducted with BAXI and Bristol Energy.

In Europe, says Tina, adoption of an as-a-service model is being used for building components, notably in commercial real estate. An example of this is elevators being charged by usage. ‘This has several benefits’, Tina explains, ‘including reducing the upfront cost. It also incentivises the service provider to ensure a long and durable service. Components recovered at the end of use in one building can be potentially reused in another, furthering the circular economy’.

Achieving scale and finding the finance

‘For the very first time, we have a defined end goal – net zero,’ says Daniel. There are some really difficult questions that are still being worked through. How do we fill the huge gap between low-level subsidy-driven policy and the scale of change required to meet 2050 targets?”  asks Daniel. The answer will need to include upstream market interventions. For example, requiring energy suppliers and manufacturers to start increasing the proportion of low-carbon interventions they make and bringing in regulation on the demand side.

Daniel also believes that the process of retrofitting needs to be made easier for householders. ‘Solving the financial problem is going to be a big part of the retrofitting solution’, he says. In terms of finance, he sees concessionary lending as the way forward as opposed to making full grants available to a limited number of people. ‘It's not only about providing consumers with loans, but also about facilitating new business models and business offers that can offer consumers a more holistic service and ensuring that consumers see the best return on their retrofit investments. For example, gas attracts virtually no carbon price, but electricity, which is getting cleaner by the day, carries a sizeable carbon price. This means consumers are not saving as much money as they as they should be in a normal market. This is an area the UK government need to address if it wants to encourage consumers to take on the initial costs in return for long-term savings’, he comments.

Retrofitting for the future: Net zero for existing building stock

In this webinar, the panel discuss the challenges in retrofitting existing stock, how can these be overcome and the best way to reduce emissions and energy use.