Why a move away from fabric first is “a step in the wrong direction” 

Paul Spence, Technical Manager for heatly, calls for caution when it comes to promoting the idea that heat pumps should be installed regardless of a property’s energy efficiency credentials. 

Paul Spence of heatly calls for caution regarding installing heat pumps regardless of a property’s energy efficiency credentials.

Following the Nesta report, ‘Insulation impact: how much do UK houses really need?’, which suggests that the fabric first approach, i.e. making homes as energy efficient as possible, is not an essential part of the UK’s current stage in the heat pump roll out, I urge installers and heat pump customers to not take this as a cue to view energy efficiency upgrades as less important. 

Nesta’s report focuses on carbon reduction, and you can’t argue with the fact that ripping out fossil fuel heating and replacing it with cleaner, greener heat pumps will reduce the UK’s carbon footprint. 

The reality is that, for most people, comfort and the cost-of-living feature far higher on their agenda than cutting carbon. Let’s be clear, I am a big fan of heat pumps – as an installer and now as Technical Manager for heatly.  

I can’t endorse, however, the idea that we should move improvement of the UK’s woefully damp and draughty housing stock lower down the list in favour of banging in heat pumps as quickly as possible. This approach could serve to dent the reputation of heat pumps and ignores the consumers on gas that simply aren’t in a position to make the switch. 

As an installer, and through my Facebook Group Heat Pumps U.K., I see first-hand the problems that arise when heat pumps are installed in very inefficient homes. One of the main problems is over-specification, which leads to higher costs and future problems. If heat loss is high, the size of the heat pump required to keep a building warm, increases. The bigger the heat pump, the more expensive it is. If, in the future the homeowner makes energy efficiency upgrades, the heat pump and ancillaries (pipes, circulators, pumps etc.) can end up being over- specified, leading to systems that use too much power and are difficult to control. 

Is better insulation essential? 

In Nesta’s report it states: “While better insulation is always beneficial with any kind of heating system, it is not an essential prerequisite for getting a heat pump. The key factors affecting a heat pump’s efficiency are system design and adequately sized radiators.  

While insulation plays an important role in reducing heat demand and can in some cases make heat pumps operate more efficiently, it is not the key factor in heat pump efficiency. Instead, having a well-designed heating system, with correctly sized heat emitters which enable a lower flow temperature, is the most important factor behind a heat pump’s efficiency.” 

This is all true, but if the energy efficiency of the house changes, as is most likely the case in poorly insulated properties, the original design will no longer be suitable. 

Crucially, without a ‘fabric first’ approach, energy bills will be prohibitive. One of the arguments I’ve seen to counter this is raising gas prices and reducing the cost of electricity. While everyone wants the latter to happen, it should not be at the expense of gas customers. 26 million homes are currently on natural gas, many of which are not in a position to switch to a heat pump; it seems unfair that they should be penalised for something beyond their control. 

Happy customers in warm homes 

This type of policy masks poor housing and poor heat pump installation with economics. We should be striving for a future where COP 4+ is the norm, which can’t be achieved without a whole house approach. 

While Nesta’s report doesn’t suggest doing away with energy efficiency upgrades, I would just be cautious of the message that could be misconstrued by some readers. Where possible, ‘fabric first’ should always be the way to go. If carbon reduction by means of a swift switch to heat pumps is the only goal, homeowners and landlords will need far larger subsidies than the ones currently available, and the industry must be prepared for greater numbers of dissatisfied customers. 

For the low carbon sector to thrive, quality is key – happy customers in warm homes that cost less to run. I’m excited to be working with heatly because it will make a big contribution to this goal; improving heat pump specification and installation accuracy, simplifying the associated processes for installers, and making the benefits of heat pumps and supporting energy efficiency upgrades easier to understand for consumers. 

What are your thoughts on the challenge of balancing the drive to electrify domestic heating with the drive to improve energy efficiency? – send them to: margaret@renewableenergyinstaller.co.uk