Conversations on Net Zero: Retrofit

Constructing Excellence

Achieving our Net Zero ambitions requires significant investment in retrofitting our current energy inefficient, existing homes and buildings. As detailed in the National Retrofit Strategy, considerable investment is being made into the Retrofit market. It represents a huge opportunity to improve energy performance and improve the lives of the people living and working in these buildings.

As our panellists stated, without tackling retrofit we are jeopardising the health and wellbeing of future generations.

During our session, we heard from Richard McWilliams, Director of Sustainability, Turner & Townsend, Mark Beirne, Partnerships Director, Cara EPS, Stewart Little, IRT Surveys and Peter Rickaby, Chair Retrofit Standards Task Group.

It has to be the whole house

Technical evidence demonstrates that single measures simply do not work and, in some cases, can make things worse. Single measure approaches look at the easy options to get to an EPC band C. Band C is simply not good enough. 

We need to consider using each building to its maximum capacity to deliver massive reductions in energy demand. This means considering the fabric first and looking at low carbon heat sources etc.

Unfortunately, many of the funding mechanisms have encouraged single measure approaches rather than deep retrofit. Many of these have been badly implemented and represented poor value for money. Issues include:

  • Poor integration, especially at the interfaces
  • Lack of understanding of ventilation and technologies used inappropriately
  • Poor commissioning, handover and advice

Delivery at scale needs market transformation

Delivering retrofit at scale requires a systematic approach that balances the physical characteristics of each building, occupant and community views with budgeting and programming skills. To do so, we need to create a market for industrialised retrofit solutions.

This requires finding new ways of financing those solutions. Richard would like to see retrofit as an iPhone for the construction industry, creating a platform for technologies and solutions to innovate from and creating desirable products with consumer pull. We need to move away from being a parasitic industry relying on government interventions to being investible and R&D active.

However, two big issues are preventing this:

  • The market isn’t there yet
  • It isn’t affordable yet

The GLA is doing innovation partnership procurement to stimulate the market and move towards an economical price point. They are looking at a framework up to 2030 to enable this to happen. At that point, the financial markets should be able to take over as the market will be at the scale and affordability levels to make it an investible market.

There needs to be a market for quality solutions (Trustmark plays an important role here), and government and procurers need to stop giving money to people who aren’t doing it right.

Process, Process, Process

This kind of local and regional market opens up opportunities for SME contractors. Mark Beirne described Cara’s role as the ‘boring bit’, but as ever, construction projects and programmes need to have a solid foundation to succeed.

Cara advocates the need to bring onboard specialists and technologies right from the start. This allows that knowledge to be part of the project from the outset, delivering real value and helping avoid unintended costs and consequences.

Many of the problems happen at the interface level. Removing those risks associated with interfaces and the gaps in the construction process can significantly improve the outcome. Vertical integration, where contractors integrate a team of best in class technologies and specialists will be fundamental to delivering innovation.

Many emerging technologies can help make industrialised retrofit work. From flying drones at scale to thermal imaging etc. Technology can help overcome some of the big issues impacting retrofit:

  • Lack of accurate data and information on the building stock
  • Motivating and empowering asset management teams
  • Communicating with and empowering residents
  • Linking procurement to best outcomes 


Careful consideration and buy-in from procurement departments will be essential to enable this market and the kind of vertical integration needed to make it work happen.

Don’t forget the standards

Many years of learning and development have got us to this point, and Peter Rickaby reminded us of the firm foundations that the current retrofit approaches stand on.

Each Home Counts brings light on the importance of Trustmark in assuring quality. The BSI Retrofit Standards framework brings together new and existing standards under PAS 2035 Retrofitting Dwellings for Improved Energy Efficiency: Specification and Guidance. This provides a robust process and framework to deliver quality retrofit. 

It’s being extended into the non-domestic sector through PAS 2038 Non-Domestic Retrofit, which aims to support effective retrofit in the UK’s 2 million non-domestic premises.

Seize the opportunity

Retrofit is perhaps the biggest challenge facing our Net Zero future, but we have an excellent opportunity to build on over a decade of lessons learnt. Our members demonstrate how alignment across funders, technology providers, contractors and standards can help us deliver quality retrofit outcomes at scale.


To find out more about our series of Conversations on Net Zero and how you can get involved, please get in touch @ [email protected]