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

Why switching from boilers to panel heaters is a bad idea

14 Jun 2021


Why switching from boilers to panel heaters is a bad idea


With the release of new anti-fossil-fuel Building Regulations on the way, word is spreading through the construction industry that we need to start ditching gas boilers and move to electric heating. But some developers have jumped the starting pistol and are quickly regretting their decision.

First, some background

In England and Wales, Approved Document Part L sets target emission rates for all new buildings. To pass this section of Building Regulations the design of the home must be more energy efficient than the target.

This regulation was released in 2013. Back then, the UK’s electricity was mostly generated through coal so the requirements naturally push builders to using gas boilers instead of electric panel heaters – the regulations are wired so that gas boilers are the more environmentally sustainable solution.

Fast forward to 2021, and the UK has just three coal power stations left; they’ve been usurped by renewable alternatives. This change means electricity, and therefore panel heaters, are now considered a greener solution than gas boilers.

So what’s the problem?

The problem is that AD L hasn’t been updated since 2013. This means Building Regulations still considers gas to be the better option, even though the Government’s own data clearly shows that’s not true.

Developments that are built to current regulations with gas boilers will perform much worse if the builder switches to panel heaters now. The plots will often miss the target emission rate completely leading to non-compliance with Building Regulations.

A builder, who in all good intentions has removed fossil fuel heating from their development, then has to spent thousands on retrospective improvements to ensure the building meets compliance with AD L. This is usually achieved by adding PV panels to the roof, or by replacing the panel heaters with a gas boiler or heat pump.

Can’t I just upgrade to the latest regulations?

Not yet – the new AD L isn’t due to be released until Spring 2022. If building control sign off is required prior to this, the building needs to comply with today’s, outdated targets.

And even after the new regulations are released it won’t be simple to swap. The proposed new targets of ADL 2021 may favour electric heating, but compliance targets will be far stricter compared to today’s regulations.

So if a builder was to upgrade to the latest regulations, they would still need to improve the dwelling emission rate by more than 30%, and may also need to upgrade walls and windows as the maximum U-Value targets are also being improved.

So what’s the solution?

It may sound like a backwards step, and it is, but the simplest solution is to stick with gas boiler installs for the time being.

The new regulations will put gas boilers and panel heaters on a more level playing field, but both options will need some form of renewable or heat recovery system to achieve compliance with the new targets.

Alternatively, the use of heat pumps works well under current regulations, and will be an even more viable solution when ADL 2021 is officially released.


The Energist Technical Team can assist with SAP calculations for your next development, and we can provide detailed analysis showing how your specification is expected to fare against the incoming ADL targets.

View all articles


Jon Ponting

Energy & Sustainability Specialist


Jon Ponting

Energy & Sustainability Specialist
View all articles

Related Services

New build residential home development

SAP Calculation

Learn More