Skip to main content

Part L changes – what does it mean for heating installers?

Authored by Marco on May 17, 2022

Heating installers

Domestic buildings are a huge strain on resources, accounting for 19% of carbon emissions and around 30% of total energy usage. Therefore, the residential housing sector is a key target for government decarbonisation strategies.

On 15 June this year, changes to Part L of the Building Regulations (conservation of fuel and power) will set new minimum standards for energy efficiency in new build homes and require heating systems to be designed to operate at a low flow temperature.

This new interim policy marks the first step towards the Future Homes and Buildings Standard, which will be introduced in 2025 and require new build homes to meet world-leading energy efficiency standards and be future-proofed with low-carbon heating.

New homes built under the Future Homes and Building Standard will produce 75-80% fewer carbon emissions compared to today’s regulations.

What changes are being introduced in 2022?

The interim uplift is designed to achieve a 31% reduction in carbon emissions through a range of measures, including:

  • Minimum energy efficiency standards for heating systems, including 92% ErP for gas boilers and a SCOP of 3.0 for heat pumps.
  • Maximum design temperature of 55°C (compared to current standard 80°C).

Will gas boilers be allowed in new homes?

Yes, but all parts of the system, including pipework and heat emitters, should be correctly sized for maximum efficiency at a flow temperature of 55°C or lower. This applies to wet heating systems that are newly installed or fully replaced in existing buildings.

Where this is not possible, for example if there is insufficient space for larger radiators, the heating system should be designed to the lowest possible design temperature that will still meet the heating needs of the property.

Setting gas boilers to lower flow temperatures has become popular in recent months as a way of reducing energy usage and lowering costs. Last winter, Octopus Energy invited its customers to take part in a ‘Winter Workout’ challenge to reduce their energy consumption and bills. Over 12 weeks, a collective £3,100,000 and 14.3 million kilograms of carbon dioxide was saved, and gas usage was cut by 12% on average.

When the Future Homes and Buildings Standard comes into force in 2025, it is unlikely that gas boilers will be able to achieve the required standards.

What new technologies will help to meet Part L?

Heat pumps are the main low temperature heating systems and demand has grown by 312% since the beginning of 2021. The policy and regulatory landscape surrounding heat pumps is slowly coming together, with the Boiler Upgrade Scheme stimulating demand in existing properties. Air source heat pumps will play a major role in compliance with the Building Regulations from 2025.

In the meantime, secondary technologies help to raise the energy efficiency of gas systems to meet Part L, including:

  • Solar PV
  • Underfloor heating
  • Smart heating controls, for example load compensation, programmable TRVs and zone control.

How can installers prepare?

These changes mark a momentous step forward for the energy efficiency of domestic buildings. Its not just new builds, lowering flow temperatures has been shown to reduce gas consumption by around 6-8% so it is a concept worth exploring for all heating installers who want to deliver cost-effective solutions to their customers.

System design is key, including room-by-room heat loss calculations, correct sizing of heat emitters, pumps and pipework, and basic design principles.

Training is straightforward for heating and plumbing installer with existing skills and experience so its really worth doing. Correct sizing not only ensures compliance with the new Part L but also helps customers make savings today, while preparing their heating systems for future technologies.

Invest in accredited training

We run a wide range of training courses to help installers prepare for Part L and the transition to low temperature heating, including:

Energy Efficiency Part L 1 Day Training Course

Air Source Heat Pump Installation Training Courses

Check out our renewables training courses page for more information.