Net zero homes: the retrofit challenge and opportunity
posted 3rd January 2024
This article was first published by Inside Housing Magazine on 19 December 2023.
Visit any of the plethora of housing conferences in recent years and you will hear more than a little noise being made about how to decarbonise the UK's 28 million homes. There are talks from a range of academics, asset directors, energy specialists and contractors on 'build tight, ventilate right', 'delivering retrofit at scale' and 'energy efficiency in heritage properties'. But delivering the right retrofit solutions will play a crucial role in meeting our 2050 net zero goals, argues Darren Phelan, Retrofit Services Lead at MSS Group, an RSK Group company.
In a 2019 report, the Committee on Climate Change stated, "we will not meet our targets for emissions reduction without near complete decarbonisation of the housing stock". Recent Office for National Statistics data showed that homes in both England and Wales constructed after 2012 had a median energy efficiency score of 83, or band B. In contrast, homes built before 1930 had a median score of 59 in England and 57 in Wales, equivalent to band E. The UK has the oldest housing stock in Europe, and more than 50% of homes were built before building regulations forced energy efficiency of building materials to be considered. The challenge is undeniable.
What does retrofitting involve?
Home retrofitting is the process of upgrading existing homes with modern energy-saving measures such as insulation and efficient heating systems and technologies. These measures can help to reduce energy consumption and lower carbon emissions by ensuring that homes are more efficient.
One of the most cost-effective and common energy-saving measures in home retrofitting is insulation. In the retrofitting world, insulation is part of a strategic 'fabric-first' approach, whereby the thermal performance of the home (i.e., how well it retains heat) is the first set of measures to be considered. Loft insulation, external or internal wall insulation and cavity wall insulation, as well as windows and doors, are all fabric-first measures. Without a well-insulated home, other measures will not work as effectively.
The question of priorities
Discussing the merits of decarbonising a home is unlikely to generate interest from homeowners. What matters to most people is how much it costs them to heat and power their homes, and how comfortable they will be.
Historical energy efficiency schemes haven't gone particularly well, and there is mistrust about new technologies. How retrofit is sold to people will make or break the mass decarbonisation effort. People need to see and hear more examples of successful retrofit projects to feel confident that their lives will improve as a result.
Energy efficiency measures - how to get it right
Historically, energy efficiency schemes have seen a great many, well-publicised problems. The lack of a common standard, poorly designed energy efficiency measures and not enough properly trained installers resulted in a range of unintended consequences in homes: damp and mould issues caused by thermal bridging or poor ventilation and insulation installed where it shouldn't have been installed, to name a few.
The Each Home Counts review, also known as the Bonfield review, was undertaken in 2016 by the UK government with the aim of improving the standard of energy efficiency measures in homes. One of the central ways of achieving this raising of standards was the introduction of PAS 2035. This is a common specification for what is called 'whole house' or 'whole building' retrofit. PAS 2035 is an approach to the installation of energy efficiency measures that considers the requirement of the entire building from a technical standpoint while considering factors such as occupancy comfort. It also looks at each building independently in the knowledge that not all properties are the same, and some - such as heritage properties - have unique challenges and require specialist knowledge when designing installation measures.
The implementation of PAS 2035 has forced all those in the energy efficiency industry to sit up and take notice. Investment has been required to upskill rapidly on both sell and buy sides, and implementation and interpretation of the standard have driven much debate in the sector. It is evident that all those involved in retrofitting homes in line with the new standards are on a steep learning curve.
Skills shortage
A retrofit revolution is upon us, but there is a serious shortage of trained people to deliver retrofit at scale, which ultimately threatens the industry's ability to meet net zero targets. It is estimated that we need about 400,000 competent retrofit professionals to decarbonise by 2050. Some funding is being made available by the government to create and upskill a capable retrofit workforce, and organisations operating in the sector are trying their best to keep up with the pace.
Hiring those with the required skills is an industry challenge, largely because those people are not yet in these roles, at least in the 'format' required. Therefore, it is up to those wanting to deliver retrofit services to develop hiring and development strategies to plug the gaps and invest in their own futures. Those operating in the industry who have not yet recognised the importance of getting up to speed with PAS 2035 are likely to be left behind.
How can retrofit be funded at scale?
The question of how to fund the mammoth task of decarbonising homes is ever present. The government has been slowly releasing funds over the past decade; however, uptake by homeowners and landlords to address the issue of energy efficiency has been slow.
More recently, the government introduced a wide range of funding schemes targeting homes with low energy ratings and inefficient heating systems and families on low incomes. These include the Energy Company Obligation (ECO) scheme and Social Housing Decarbonisation Fund (SHDF), as well as the Optimised Retrofit Programme in Wales. For private homeowners, the opportunity to access funding is limited for the majority who do not fall into the category of low income or priority property. The cost of installing energy efficiency measures would then rely on a hefty outlay from homeowners that, in many cases, wouldn't show a return on investment for a decade or more.
Achieving decarbonisation through retrofitting
It is now widely accepted that, to meet net zero targets, home retrofitting is a necessity. We need to do it fast, and we need to do it without producing unintended consequences for residents. Funding is 'bitty' and is currently preventing long-term investment, but the framework to achieve the desired outcome exists. It requires a willingness and an investment from organisations to prepare a workforce that can deliver a green future for the UK's existing housing stock.
Education will play a huge part in the country's decarbonisation ambitions. How we use energy in our homes and the technologies on offer may require society to make some fundamental changes, although this is possible without a decrease in quality of life. As technologies improve and as the noise changes from confusion and mistrust to a quiet confidence from households that their lives can be improved and that net zero isn't just a government slogan, adoption will happen, and a greener future awaits UK homes.
Darren Phelan is retrofit services lead at MSS Group, an RSK Group company and a specialist in building surveys and assessment. Darren has 20 years' experience delivering survey and assessment services to the social housing sector and has more recently extended his expertise to include managing the delivery of retrofit assessments. MSS provides retrofit assessments, air tightness tests, LiDAR scans and other related services and has delivered projects across 1500 properties for social housing landlords in 2023 so far.