Housebuilders must course correct on clean heat

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Introducing the Housebuilders Clean Heat Index: too many house builders are delaying the transition to clean heat in their developments, says Ned Lamb, calling for a wide-scale shift to clean heat.

Decarbonising the energy used to heat our homes is a critical component of the UK’s mission to become a net zero nation. Of the 454.8 mega tonnes of carbon dioxide equivalent (MtCO2e) emissions the UK is responsible for each year, home heating accounts for 17%. For the country to get to net zero by 2050, total building emissions will need to reduce to between 0 and 2 MtCO2e.

A massive transition is needed. Not only does the fabric efficiency of our housing stock need to improve, there needs to be a whole-nation switch from fossil fuel-based to renewable energy-based heating systems.

While a range of approaches will achieve this, examples from the UK and Europe, alongside a growing volume of academic and industry research, suggest heat pumps will be the most common alternative to gas boiler-based heating systems. Depending on housing type and density, forms of heat pumps and renewably-sourced heat networks will power domestic heating and hot water across the country.

We can’t delay doing this any longer. For existing housing this transition will take time, requiring more supportive and long-term policy, regulation, and incentives. These will drive homeowner demand, unlock learning economies, and encourage the development of a high-skilled workforce. In their absence (not enough is being done today), not only will homeowners fail to prioritise the fabric efficiency upgrades needed to make their homes more thermally efficient, they’ll also be stuck with inefficient, gas-guzzling boilers for longer than necessary.

But what about the housing developers building our homes of the future?

In the year ending March 2022, just over 200,000 dwellings were completed in the UK, most of which large-scale housebuilders have been responsible for. Are these homes using low carbon heating and energy? The truth is, they’re not. Not anywhere near enough.

Eight years on from the zero carbon homes proposal being scrapped – it proposed housebuilders build zero carbon homes from 2016 – by the Cameron government, more than a million homes have been built. And while these are being built to higher fabric efficiency standards, the vast majority were connected to mains gas and continue to be. This has been a major, but under-discussed policy failure, and millions of homeowners, often first-time buyers, will be left bearing the costs of retrofit works to make their homes compatible with clean heating alternatives.

The Housebuilders’ Clean Heat Index

With a renewed focus on domestic energy needs following Russia’s war on Ukraine, and strengthened decarbonisation commitments by the UK Government, how we heat our homes is being pushed up the agenda again.

Encouraged by Redrow’s decision to go ‘heat pump as standard’ ahead of the introduction of the Future Homes Standard in 2025, I wanted to analyse the progress of other major housebuilders. In doing so I developed the Housebuilders’ Clean Heat Index, which evaluates the progress and public commitments of the UK’s 50 largest housebuilders (organised by revenue).

Broadly, the index highlights widespread upselling of energy-efficient properties that minimise heat loss versus a typical Victorian house, set against a massive under communication of the types of heating systems that homes are being sold with. This is a form of greenwashing and a marketing ploy to play down or ignore any financial burden that may be placed on homeowners if they need to later retrofit their house and heating system to be less carbon intensive.

You can check out the Housebuilders’ Clean Heat Index here.

The findings – a worrying picture

The laggards

30 of the 50 major housebuilders fall far short of the mark in terms of their commitments to clean heat. In short, they’ll begin their transition at the last possible moment and their inaction will mean hundreds of thousands of new homeowners over the next couple of years will move into new homes using mains gas for heating.

In the balance

14 housebuilders are visibly involved in clean heating developments and pilots or have made strong commitments to deliver zero carbon homes, but haven’t yet made a firm commitment to build all new homes using clean heat before the Future Homes Standard arrives in 2025.

However, there is real innovation happening in pockets. For example, Top 10 housebuilder Taylor Wimpey has secured planning permission for all future phases of its Chilton Woods development to be powered by a heat network, powered by large scale air source heat pumps. The network is being developed with utility provider, GTC, and will supply homes with heat and hot water. Vistry Group is building 100+ developments with air source heat pumps.

While these show progress, this is largely confined to pilot developments that are limited in scale. We are beyond the point of needing new pilots, and for the most part, pilots should increasingly be seen as a delay tactic when the technology and systems for clean heat are known to work and financially viable.

The leaders deserve praise

Thankfully, some housebuilders are leading the pack. As noted above, Redrow’s announcement is welcome. Also worth mentioning are MJ Gleeson Group, who has already trialled the use of air source heat pumps in developments and has announced that from June 2023, all new homes will be installed with the technology.

In 2021, Telford Homes announced that all new planning applications had pivoted from gas-led infrastructure to fossil-fuel free, decarbonised electrified systems – either via air or ground source heat pumps. Weston Homes is removing gas as an energy source within all future homes, and in many developments already underway. From July 2023, Hopkins Homes has promised to fit the majority of new homes with air source heat pumps.

And while air source heat pumps are the most cited replacement technology for gas boilers, ground source heat pump-based networks are beginning to pick up serious momentum too; most notably across the existing housing stock and new build developments. Those with a keen interest in the sector will have been sleeping under a rock to miss the wave of positive coverage about Kensa Utilities’ Heat the Streets scheme in Stithians, Cornwall.

Kensa’s approach is offering the holy grail of clean heating, hot water and stable bills without significant upfront costs. But others are delivering similar projects already and will be key players in the market too. Take Rendesco, a contemporary of Kensa in the geothermal and ground source heat pump market; they’ve already delivered 61 ground source heat pump-based networks providing low-cost heating and hot water for over 2,600 individual dwellings for Churchill Retirement Living. With proof of concept in place, and further projects completed with McCarthy Stone, Rendesco is now gearing up to roll out its upfront funding model to large scale housebuilders this year.

As the climate crisis worsens and the need for energy security grows, energy systems that are less import-reliant – such as those endorsed by Kensa and Rendesco – should become mainstream. We will hear a great deal more about heat networks, ambient heat networks, and heat pumps over the next decades; and they’ll be used interchangeably depending on the housing type and density. There isn’t a single perfect solution, nor does there need to be. But with proof that so many clean heating solutions work and are financially viable, it’s time for housebuilders to smell the coffee.