Changes to Part L of the Building Regulations; what do they mean for the industry?

The significant changes to Part L of the building regulations, introduced on 15 June, aim to improve the efficiency of new and retrofit heating systems. These changes are a necessary step to reducing emissions from buildings and will be followed in 2025 by the introduction of an even more ambitious Future Homes Standard. Heating engineers need to take notice of the changes that took place on 15 June and the general direction of travel as required skills and measures required to install heating systems evolve.

A core objective of the 15 June update has been to deliver a 31% reduction in CO2 for new homes compared to previous Part L regulations. This is to be achieved by a combination of tighter standards for fabric efficiency and the performance of heating systems in new homes mainly through the installation of heat pumps. However, the updates go further to cover a wider range of heating system installations in the retrofit space creating new requirements for most heating engineers.       

Some of the changes that stand out by impacting in a lasting manner the wider heating installation market are:

1.           TRVs are now mandated. Heating systems in new dwellings, or when a heat generator such as a gas boiler is replaced should be combined with a thermostatic room control (i.e. a TRV) in each room. TRVs are common practice but this change mandates them with all new heating system installations.

2.           Where a new heating system is newly installed or fully replaced in an existing building, all parts of the system including pipework and emitters should be sized to allow efficient operation at a maximum flow temperature of 55°C or lower. This is an important change that will require the proliferation of best practice, such as hydraulic balancing, which is now made much easier for the installer by the introduction of Drayton auto-balancing TRVs.

3.           Replacement heating systems in existing homes must not produce more CO2 eq. per kWh of heat, and not have a higher primary energy demand per kWh of the appliance being replaced. This is important as it sets out a pathway for continues efficiency improvement that we would expect to be tightened further in future iterations of the regulations to encourage the installation of more efficient heating solutions such as heat pumps. 

Maximising efficiency

In addition the new regulations make it clear that systems “should be commissioned by testing and adjusting as necessary to ensure they use no more fuel and power than is reasonable in the circumstances.”

Do’s and Don’ts:

• Do a heat loss calculation before anything
• Don't oversize the boiler you're fitting
• Do flush and clean the system then add inhibitor in accordance with BS 5793
• Do balance the radiators to avoid any cold spots around the home and improving boiler efficiency - our new Auto-balancing TRVs are perfect to make this job super speedy         

These changes mean that all heating engineers need to increasingly invest in their familiarity with installation best practice and established technologies such as TRVs. These will be necessary to meet new requirements but also prepare for the emerging heating market that will be increasingly dominated by efficient heating systems such as heat pumps. At Schneider we are excited about change and continue investing in our partnership with heating engineers and the development of solutions that facilitate the transition such as our new Drayton auto-balancing TRVs used to balance system flow rates from the TRV.

To learn more and ask questions of our expert, Clare Jackson from Gemserv, join The Drayton Community Facebook Group for our Live Q&A on Thursday 28th July.