Energy efficiency in housing: it’s time to act not just talk 

When it comes to improving the energy efficiency of housing in the UK, it seems that we are still having the same conversations we were having 10 years ago. Why is this? It’s certainly not because we don’t have the technology – we do. And it’s not because our modelling hasn’t improved – we have better, more accessible data than ever before. Our simulation platform, EnergyFlex, from Cambridge’s Energy Efficient Cities initiative, has, for the past decade, been modelling what changes will be needed to improve each house’s energy efficiency. We can even factor in economic uncertainties and the impacts of different policies, as well as figure out how to optimise existing energy networks.

Ten per cent of global carbon emissions come from heating and lighting our houses, so if we’re to reach net zero, things like insulation, which reduce demand for energy, are as crucial as decarbonising the grid. So why are our houses not becoming more energy efficient as fast as they should?

Retrofitting existing homes has well-known issues: people live there (in the case of flats, lots of people), it’s disruptive, it’s expensive and it’s inconvenient. Also, efficiency measures first upgrade living standards before yielding any financial savings. But other countries in northern Europe also have ageing housing stock, and they’re doing much better than we are.

One problem is that we are not building new housing to a high enough standard. If we were, we would have a diminishing problem. New housing built to even a basic modern standard should require very little heat, and we should also be thinking about ventilation to manage increasingly hot summers. But we’re not, because we have a severe lack of any regulatory mechanisms for either penalising or incentivising building standards. We cut costs because we don’t see the value – we’re not valuing health in relation to housing, for example, and this is increasing the NHS burden from the mental and physical issues attached to poor housing.

There are ways to incentivise customers and markets without public funding, but we need a top-down effort to make energy efficient housing desirable and fundable, to make it easier for markets to be flooded with energy efficiency products.

We also need to start building up skills, and contractual and construction pipelines for decent standard housing. We are seeing some skills transfer from academia, with our engineering graduates able to work with councils and industry on improving energy efficiency, and consultants and SMEs learning to use our models. But the pipelines for products, and the incentives for skills, are not there.

What we also need is a much more nuanced and tailored approach to policy. Our own research into homes built since 2000 has shown that energy efficiency varies greatly depending on where you are in the country, with homes in the north, which typically have poorer quality housing, less energy efficient than homes in the south. Then it depends on the ownership typology; someone in socially rented housing will need different incentives to a private landlord, and offering this tenant some money off an expensive heat pump just isn’t going to work.

Our modelling, until recently, also neglected this one crucial element: the humans who live in the houses. So since 2013, we have worked with urban geographers and urban analysts to plug the socioeconomic context into our models, creating synthetic populations of households specific to geography. We can now calculate the likelihood of uptake of heat pumps in certain areas, for example.

Achieving energy efficient housing is complex and we haven’t had the stability in governance to focus on it. And that’s why we’re still talking about it. We have the understanding, we have the tools, we just need to get on with it!