Find out how the new AD L will impact your upcoming developments AD L White Paper

Part L: Gas Boiler or Heat Pump?

07 Nov 2019


In this series of articles, we aim to answer some of your questions about the upcoming changes to Approved Documents L and F, SAP methodology and the Future Homes Standard.

Current proposals suggest these regulations will be coming into force in England from October 2020. Contact us with your own questions about the regulation changes, or to discuss our training seminars and workshops.


Gas boiler or heat pump?

The new regulations work in such a way that heat pumps become the preferred heating option for new builds, but gas boilers and panel heaters will also have their part to play and shouldn’t be written off.

Ever since the Target Emission Rate was first introduced into Building Regulations, gas boilers have been the preferred heating system by a large majority of construction companies. But earlier this year the Government announced plans to phase out fossil fuel heating in new homes by 2025 as part of their headline grabbing drive to reach net zero carbon by 2050.

The release of the Future Homes Standard and the proposed changes to AD L will set our industry on a fresh course where heat pump solutions will be one of the most viable options for reaching compliance with Building Regulations.

Under the proposed changes it will still be possible to achieve compliance with gas or LPG boilers, but it won’t be as easy and you may need an enhanced fabric specification with thicker walls and triple glazed windows, plus photovoltaic arrays.

By using a reasonable all-round specification with a heat pump, a developer should be able to meet the new targets more easily.

There are three targets in the proposed AD L. The first is the Target Emission Rate.

Electricity has always had a high carbon footprint, but as the UK switches on more solar and wind farms and switches off coal and gas power stations this fuel is becoming greener. This means electric heating systems will perform better against the new TER. This includes panel heaters as well as heat pumps, but heat pumps are three times as efficient.

The second target is the Primary Energy Rate (TPER). This looks at every kilowatt of energy required to run a house, plus the energy used to produce that kilowatt of power in the first place. The UK’s electricity grid has been made far more efficient in recent years but it’s still not as efficient as our gas network. That said a heat pump, with its high efficiency, will perform much better than a gas boiler against this target. Panel heaters are certain to struggle in this section.

The third target is Household Affordability. This measures how much it will cost to heat a house and is being introduced into the regulations to help reduce the number of fuel poverty households.

Despite common belief, the running costs of gas boilers and heat pumps are quite similar. Heat pumps may use less energy, but electricity costs more so the two factors balance out. Panel and storage heaters cost far more to run, but as yet the threshold for the HA target hasn’t been set.

The Energist Technical Team can produce an AD L 2020 report to show how your current specification will fare against the new targets, and how switching to a heat pump or PV solution may help you stay on the right side of building regulation targets.

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