12th June, 2023

Demystifying Part L of the Building Regulations


Did you know that from June 2023 all heating engineers must comply with the updates to Part L of the Building Regulations?

We’d like to think so. However, in our recent survey of 150 heating installers, almost half (48%) admitted that they are not aware of the updates to Part L and over a third (35%) said that they do not keep up to date with changes to regulations.

On top of this, our research revealed that almost a third (30%) of installers have tried to read Part L of the building regulations but felt that it was confusing or difficult to understand and over a quarter (27%) said that they didn’t understand the building regulations at all.

However, while there may be some confusion when interpreting Part L, the deadline to comply is fast approaching and from June 2023, all projects will need to adhere to the new regulations. So, it is essential that installers, merchants and specifiers work to gain an understanding of the legislation and how it will impact their work.

With all of this in mind, we wanted to investigate where the confusion lies for heating installers and what we can do to help the industry to ensure a smooth transition.

Are installers aware of how Part L will affect their work?

With half of our respondents saying that they had not read the updates to Part L, we were intrigued to find out how many of them are aware of how it will affect their work.

When asked, 23% of installers admitted that they know that the regulations might affect their work, but haven’t read them and 36% said that while they have read the building regulations, they still don’t understand how the changes will affect their work.

To delve a little deeper, we asked installers about some of the biggest changes to the building regulations. We found that over half (52%) were not aware of the new maximum flow temperature of 55 °C – which is a critical amendment to the legislation. We then asked whether installers are aware of the need for heating controls to be installed in each room/zone of a dwelling and a worrying 55% said that they did not know this.

These weren’t the only regulations that installers were unfamiliar with. In fact, we asked them about a range of elements that have been introduced as part of the updates to Part L. Here’s what they said:

  • 51% are not aware that gas boilers will be required to have a minimum energy efficiency of 92% (ErP)
  • 52% are not aware that new wet central heating systems (radiators and UFH) should be sized for a maximum flow temperature of 55°C
  • 52% are not aware that heat loss calculations will now be required for every room in a dwelling, rather than just for the dwelling itself, when installing a replacement boiler
  • 53% are not aware that all exposed pipework will need insulation in a job where a boiler or cylinder is replaced
  • 53% are not aware that there will be a requirement to sign a Buildings Regulations Compliance Report (BREL) and/or photographic evidence of build quality may need to be provided to the homeowner
  • 55% are not aware that the updates to Part L of the building regulations are intended to reduce carbon emissions in homes by 31%

Where do the updates apply?

Through our research it became clear that there is a lack of clarity amongst installers when it comes to understanding which jobs Part L will impact, even in instances where they have read the Approved Document.

Of those surveyed, 37% of installers think that because they only work on existing dwellings, their work won’t be affected and 23% said that they are not even aware that building regulations affect new builds. However, these statements are not true. The updates to regulations have been introduced as a stepping stone towards the Future Homes Standard and will have a major impact on how heating systems are designed, specified and installed in both new builds and existing dwellings. So, everyone in the supply chain needs to familiarise themselves with the legislation and what they need to do to ensure compliance.

In addition, installers were also wary about how compliance would be enforced in small retrofit projects with almost a third (30%) of respondents saying that they don’t think there is any way it could be policed. In reality, the regulations state that there will be a requirement to sign a Building Regulations Compliance Report (BREL) and photographic evidence of build quality may even need to be provided for some projects. A failure to do so could result in serious penalties and costly fines.

Nonetheless, while our research found that awareness is generally lower than we’d like, we did find that younger installers seem to be embracing the changes. In fact, 59% of installers between the age of 25-34 said that they have read and understood how the building regulations will affect their work. This is positive to see as the younger generation of installers will play a critical role in helping the industry to reduce carbon and, eventually, meet net zero.

Supply chain collaboration

All in all, our research found that a concerning number of installers aren’t aware of the updates to the building regulations. This is a worry as the transitionary period, which has been in place over the past year, should have provided an opportunity for installers to ensure that they have researched and understood the regulations before they become enforceable.

However, if installers – or anyone involved in the industry – still feels unsure, then now is the time to familiarise yourself with the building regulations and exactly how they will impact your work.

The pressure shouldn’t sit solely with installers. In fact, manufacturers, merchants, specifiers and trade bodies should all be educating themselves and sharing knowledge across the supply chain to ensure a smooth transition.

At Polypipe Building Products, we’ve been working alongside installers throughout the year to support them through the regulation updates. In fact, we’ve recently published a number of simple blogs explaining the key updates to Part L right here on our Future Homes Hub.

Our team are also on hand to provide in-person technical support to anyone who needs it. If this sounds like it could be of interest, please get in touch with us below.

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