London’s ageing buildings threaten to derail the capital’s net zero ambitions

Around 65 per cent of London’s buildings pre-date modern energy standards, creating a major challenge for net zero.

London’s architectural appeal is one of its defining strengths, but much of its commercial property market still operates inside buildings designed for a very different energy system. Around 65 per cent of the capital’s buildings were constructed before 1980 (Greater London Authority, 2023), leaving large parts of the estate reliant on heating infrastructure developed long before modern efficiency standards or net zero targets existed. According to decarbonisation platform, SaveMoneyCutCarbon, these legacy systems are now driving higher operating costs across London’s commercial buildings. As older technologies consume more energy and deliver heat far less efficiently than modern alternatives, legacy heating infrastructure across the capital’s commercial estate are locking businesses into higher energy use.

Across the UK there are around 1.9 million non-domestic buildings (DESNZ, 2023), many of which rely on older heating systems designed around fossil fuels and inefficient energy distribution. In practice, these systems often heat entire building volumes rather than focusing energy where it is needed, leading to higher energy consumption and avoidable operating costs.

Commercial buildings account for around 18 per cent of national carbon emissions (UK Green Building Council, 2022), placing the performance of existing buildings at the centre of the UK’s emissions profile and making improvements to older building infrastructure critical to meeting climate targets.

For London’s commercial estate, the transition to net zero is therefore largely a retrofit challenge. Modernising heating systems, improving building controls and introducing electrified heating technologies are becoming central to reducing energy demand while preserving historic buildings, an area where decarbonisation platforms such as SaveMoneyCutCarbon are helping organisations accelerate upgrades across existing estates.

Technologies that deliver heat directly within occupied spaces, rather than heating entire building volumes, are increasingly being explored as practical retrofit solutions for older buildings.

Mark Sait, CEO of SaveMoneyCutCarbon said: “A lot of older heating systems were built for a different era and they just are not suited to how buildings are used now. You still see whole floors or entire volumes being heated when only parts of the space are occupied, with very little control over where energy is actually going. That is where retrofit comes in. It is about taking what is already there and making it work properly, using better controls, zoning and more efficient, often electrified solutions. If you can reduce waste first, you immediately bring costs down and put yourself in a much stronger position when energy prices move, which we have seen again with the latest oil volatility.

“Most organisations do not need to start with major disruption. The quickest gains usually come from understanding how the building is performing today and then tightening it up. Controls, sensors, scheduling, lighting and heating optimisation are all relatively straightforward changes that can have a meaningful impact on energy use and cost. Once that waste is taken out, you are in a far better place to make bigger decisions around heating transition or electrification, because you are working from a more efficient baseline and a clearer financial case.

“In London, this is really a retrofit story. The majority of buildings are already standing and a lot of them are running on infrastructure that was never designed for current energy costs or net zero targets. You are not going to replace that stock, so the focus has to be on improving it. When retrofit is approached in a structured way, starting with proper engineering assessment and followed by phased upgrades, it delivers both cost reduction and carbon savings. Just as importantly, it gives building owners a bit more control and resilience when the energy market shifts, which is becoming a more regular part of the picture.”