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Infrastructure planning should not be judged by how efficiently it delivers a predicted future, but how effectively it preserves society’s ability to adapt when the future arrives differently.

The evidence on which the UK’s heat network policy was based foresaw a future that never arrived. This is a consequence of drawing the boundary too tightly around the system. A policy drive towards decarbonisation perhaps being put ahead of adaptability and human comfort.

District heat networks, specifically those across the Greater London region of the United Kingdom, illustrate the limitations of forecasting and policy when uncertainty and complexity are the only guarantees.

Modelling as they did for static loads, residents have been faced with site-specific human impacts that were the product of a policy that prioritised decarbonisation over comfort. Something that the Future Homes Standard is hoping to remedy?

• Corridors and apartments overheating due to cumulative heat losses from pipework circulating hot water 365 days a year.
• Complex landlord heating systems contributing to larger responsibilities for central maintenance funds.
• A ‘fabric-first’ approach to insulation and air tightness, but a prohibition on electrically powered comfort cooling (AC) and restrictions on natural ventilation on acoustic grounds that contribute to overheating.

The decarbonisation of heat generation has served the policy purpose of moving the energy intensive generation of the energy that contributes to producing heat beyond the Greater London limits. So we aren’t burning gas in London as much, great, but is our energy consumption / efficiency as a city improving? How should we measure performance? Does this move the dial compared to existing stock that still relies on natural gas? How many ‘all-electric’ buildings are there compared to ‘gas-fuelled in London? Answers on a postcard, please…

The lag in the delivery of district heat networks (DHNs) has necessitated the rollout of commercial-scale heat pumps across all new high density residential buildings in London, increasing electrical loads. The rigidity of this policy, and the tightness of the boundary drawn around it, means that the rapid acceleration of AI data centres and their demand for energy within Greater London has put immense strain on housing, with an energy scarcity being managed through ramped connections over multiple years. Meanwhile the data centres churn away merrily.

In readiness for DHNs, developers and contractors are required to ‘future-proof’ infrastructure in residential buildings suitable to receive a connection. It is this approach that requires buildings to have extensive pipework distributions as part of the backbone of the building’s systems. If a plot-by-plot approach to generation could be taken, residents would have more control over their heat generation and storage, and would also have clearer responsibility for the costs, as opposed to the overheads associated with complicated landlord networks that rely on large scale pumping and storage in a central plant room.

What would the impact be if an adaptive, non-prescriptive policy could be rolled out? How wrong would it all go if flexibility was to be offered? Like the Building Regulations themselves, can we work towards becoming an outcomes-based economy as opposed to a prescriptive one.

Until then, new residential buildings in London will continue to run hot.