Why Flats Must Not Be Forgotten in the UK’s Warm Homes Drive

The Numbers: Flats Are Britain’s Hidden Homes

Roughly one in five UK homes is a flat — more than 5.5 million properties — and about 1.8 million sit within social housing portfolios. In many cities, flats dominate: some local authorities manage estates where they account for the majority of homes. Much of this stock dates from an era when energy efficiency was, at best, incidental.

The heating systems in these buildings reflect that history. Around 40% of flats still rely on electric storage heaters, while another 20% use direct electric systems such as panel heaters — both costly to run under current tariffs. Gas boilers account for roughly a quarter of properties, with communal or district heating systems making up the remainder. This mix of legacy technologies complicates policy: there is no single, scalable solution, even if recent schemes have often assumed otherwise.

The Retrofitting Reality: Why Flats Are Different

Retrofitting a flat is fundamentally different from retrofitting a house. The constraints are physical, technical and institutional. Outdoor space for heat pumps is scarce. Shared walls and limited access routes complicate upgrades. Electrical capacity in older buildings can be insufficient for modern demands.

And for social landlords, the operational barriers are just as significant: coordinating works across multiple tenancies, securing consent from leaseholders, and managing disruption in densely occupied buildings.

The Urgency: Getting Flats Off Gas

All of this makes the transition away from gas — a central plank of the UK’s net zero strategy — particularly fraught for flats. The phase-out of new gas boilers from 2035 is clear enough in principle. In practice, flats are rarely straightforward candidates for replacement technologies. Large-scale conversions to communal or district heating systems are possible, but slow, capital-intensive and administratively complex. 

The Regulatory Catch: Why District Heating Remains a Niche

Even under optimistic assumptions, only a minority of flats are likely to connect to district heating by mid-century. These systems are well suited to dense urban developments, but scaling them across existing social housing stock has proven difficult. Part of the problem lies in regulation. Social landlords operating heat networks are treated, in effect, as energy suppliers, subject to Ofgem oversight and compliance requirements.

While consumer protections are necessary, the burden can be disproportionate. Many housing associations are reluctant to assume the financial and regulatory risk of running heat networks, particularly when layered onto already challenging retrofit programmes. The result is hesitation — and a technology that remains, for now, niche.

What’s Left: Outdated Electric Heating and Rising Costs

With gas constrained and district heating limited, many landlords fall back on electric solutions. But the legacy systems still common in flats are often inefficient and expensive, contributing to fuel poverty and poor health outcomes.

Cold, damp homes are linked to respiratory illness and excess winter mortality, with the burden falling disproportionately on low-income urban residents.

The Technology Gap: Heat Pumps Aren’t the Answer for Flats

In this context, the government’s strong emphasis on heat pumps looks increasingly incomplete. Heat pumps are an effective technology in the right setting, but flats are rarely that setting. Air-source systems require external space and can introduce noise and aesthetic concerns; ground-source systems demand infrastructure that most buildings simply cannot accommodate. Without building-wide interventions, heat pumps are often impractical for individual flats.

This leaves a gap between policy ambition and housing reality. If heat pumps are the flagship solution, flats risk becoming the awkward exception.

Future-Facing Solutions: Smarter Ways to Heat

A more pragmatic approach is emerging. Flats require heating solutions that are compact, flexible and responsive to both physical constraints and energy pricing. Technologies such as infrared panels, advanced electric storage heaters and thermal batteries are increasingly capable of meeting these needs. Combined with digital controls and, where possible, rooftop solar, they offer a way to improve efficiency without wholesale structural change.

These systems are not without limitations, but they share an important advantage: they can be deployed incrementally, with less disruption and lower upfront cost than large-scale retrofits. For social landlords managing tight budgets and complex estates, that flexibility matters.

Policy may now be catching up with this reality. Under the revised EPC framework for social landlords announced in January, heating has become one of three metrics that can independently deliver an EPC rating of C. This is a subtle but important shift. It allows landlords to meet regulatory targets through well-designed heating upgrades, rather than relying solely on fabric improvements or major infrastructure projects.

The implication is clear. A carefully specified combination of modern electric technologies - particularly when paired with smart controls - can achieve compliance more quickly and with less disruption. For a sector where time, cost and tenant impact are all binding constraints, this reframes the challenge from wholesale transformation to targeted optimisation.

Warmth as a Public Health Imperative

None of this diminishes the broader point: warmth is not merely a technical objective. It is a matter of public health and social equity. Cold homes exacerbate inequality, concentrating harm among those least able to mitigate it. A credible decarbonisation strategy must therefore prioritise the hardest-to-treat homes, not just the easiest.

For social landlords, the task ahead is demanding but unavoidable. It will require experimentation with new technologies, closer collaboration with suppliers, and sustained engagement with policymakers. Above all, it will require recognition that flats are not a marginal case but a central one.

The Warm Homes Plan presents the right ambition. But to honour its promise, policymakers must recognise that Britain’s path to Net Zero runs not just through leafy streets lined with heat pumps, but up the stairwells of high-rises and along the corridors of social housing estates.

Those who manage and maintain flats - the unseen custodians of much of the nation’s housing stock - are on the front line of this transition. They deserve not only regulatory clarity and funding, but also a voice in shaping the solutions. For if the future of heating is to be just, it must be a future that warms everyone, flat by flat.