The Ingredients Of A Successful Zero Carbon Retrofit Programme
Zero carbon retrofit has been in the news a lot lately. This was partly prompted by the announcement of grants to support the installation of millions of heat pumps.
Cue the inevitable flood of comments about why this won’t work, why we should be doing something else, and a series of anecdotes from people who installed heat pumps with mixed results.
What all of this goes to reinforce is that net zero carbon is a complex, multi-faceted issue. Installing a heat pump, ideally powered by renewable energy, will be a viable solution for some homes. For many it won’t, on its own, be the answer.
So what will it take to succeed? What are the essential elements of a successful zero carbon retrofit programme?
The Whole House Approach
This is probably the most fundamental point. A home is its own ecosystem. Installing an air-source heat pump in a poorly insulated home will just make it harder to heat – particularly when the external temperature plummets in midwinter.
For the heat pump to heat the home effectively it will probably be necessary to install larger radiators or underfloor heating. In many cases, the home will need to be better insulated and airtight before a heat pump is a viable option.
Avoiding Unintended Consequences
Making a home airtight is important. But, controlled ventilation will be needed to create a pleasant internal environment and eliminate the risk of damp and mould. Proposed insulation treatments and replacement doors and windows also need to be analysed carefully to avoid introducing damp or thermal bridging issues.
The obvious conclusion from the above is that a detailed understanding of the current stock condition is essential before any plans and budgets can be drawn up. Work can then be sequenced to ensure that retrofit programmes lead to a positive outcome for residents and the stock.
Planned Supply Chains
There’s a vast logistical challenge to ensure that specialist skills, materials and equipment are available when needed. This will inevitably call for a long-term approach to procurement and supply chain management to achieve best value and avoid interruptions to the programme.
Net zero carbon retrofit projects are not new, but they’ve never been attempted on this scale. There’s also a big difference in mindset between a homeowner who has commissioned an energy efficiency retrofit and a tenant who hasn’t asked for it.
How will this be reflected in energy consumption behaviour after the retrofit? And what effect will retrofit programmes have on real-world energy use? These factors will have to be monitored and the results fed back into a process improvement loop.
And this brings us to the critical issue of keeping tenants informed and engaged. A BEIS survey in 2018 found that just 27% of the population were aware of what an air source heat pump was. That percentage has undoubtedly grown, but we need to be aware that there’s a gap between the understanding of tenants and social landlords.
Zero carbon retrofit should be good news as it will make millions of homes more comfortable, healthier and cheaper to heat. But we should never assume that the benefits are self-evident.
And as people become better informed, they may also become impatient. Clear information about priorities and plans will be essential.