Dan Love, Head of Commercial at Polypipe Building Products, explains the impact of regulation changes
Last year England, Wales and Scotland all introduced tougher measures when it comes to the energy performance of homes across the UK. The requirements were introduced under Part L (Conservation of fuel and power), Part F (Ventilation) and Part O (Setting Standards for overheating in new residential buildings) and are the biggest set of Building Regulation updates to impact the heating sector in over a decade.
The changes were introduced in England in June 2022. Since then, however, the industry has been in a grace period. During this period, projects have been able to continue under the old regulations as long as they began within 12 months of the new regulations coming into force. Now, almost a year down the line, heating engineers – whether they install oil, gas or renewables in either existing homes or new builds – need to ensure that they are familiar with the changes.
A step in the right direction
The updates to the Building Regulations are part of the Government’s ambitious goals and ongoing strategy to reduce carbon emissions. They serve as a stepping stone to the Future Homes Standard, which is due to come into force in 2025, and will mandate that all homes in the UK produce at least 75% less CO2 emissions relative to the previous 2013 version of the Part L approved document. This will mean that from 2025 onward, all newly built homes will be net-zero-ready and will not need retrofitting in the future.
Reaching a reduction of 75% less carbon emissions is an ambitious target, which is why the changes to Building Regulations Part L have been introduced in the interim. The aim is that they will ease the transition between the old and new energy efficiency regulations and help the industry to achieve a 31% reduction of carbon emissions in new and existing homes prior to the Future Homes Standard coming into force.
Staying under the limit
Currently, a building’s energy performance can vary depending on resident behaviour (for example, opening windows when it’s too hot in the summer or when they cooking). From 15th June 2023, the thermal performance of a new building must see improvements in external wall U-values (down to 0.18W/m2K). The heating systems for such new builds will also have to be designed with a maximum flow temperature of 55°C or lower, therefore pointing towards low-temperature, low carbon systems.
However, while previous versions of the Building Regulations only applied to new builds, the 2022 updates also cover some areas of existing homes. This means that newly installed or fully replaced wet heating systems in existing dwellings will also need to be designed to meet the needs of the dwelling at the same maximum flow temperature of 55°C or lower – much like the legislation for new builds. So, it is crucial that engineers understand the new regulations, even if they only work on retrofit projects.
To achieve this much lower temperature, the heat emitters in a home will need careful consideration and radiators may need to significantly increase in size, presenting space and aesthetic issues. For example, to provide 900 watts of heat output with a flow and return of 45°C/35°C, a double panel radiator would need to be 1,800mm L x 600mm H compared to 1,000mm L x 600mm H when using 75°C/65°C – which is almost double the size. This means that it is likely installers will need to explore alternative emitters that have been designed to run at 55°C, as laid out in the new regulations.
Heat emitters with a larger surface area, such as underfloor heating, are an ideal alternative as they can run at lower temperatures – between 33-55°C rather than 75°C. This also makes underfloor heating (UFH) ideal for use with low temperature boilers and renewables, such as heat pumps, as the demand it places on energy sources is significantly less. In fact, due to its ability to run at lower temperatures, UFH can perfectly accommodate the optimal coefficient of performance (COP) for heat pumps, which is attained when they run at 35°C.
However, there may be certain cases where it’s not possible to achieve a flow temperature of 55°C, either in properties where there is insufficient space for larger radiators, or where the existing distribution system is provided with higher temperature heat from a low carbon district heat network. Where this occurs, the new system will need to be designed to achieve the lowest flow temperature possible, whilst still meeting the heating needs of the property.
The tip of the iceberg
Although Part L contains major changes to the way heating systems are installed in new builds to gear up for the Future Home Standard, many aspects of the new regulations will also have a large impact on how engineers design and install systems in refurbishment and retrofit projects.
The lower maximum temperature is one of the key elements of the Building Regulations that will have a direct impact on domestic installers across all projects – both new builds and existing homes. However, the regulations don’t stop there. Installers will also need to ensure that they are insulating pipework, conducting room-by-room heat loss calculations, and implementing heat zones and controls within a property – whether new or existing.
So, it is crucial for any professional operating in the industry to get a firm hand on the updated regulations ahead of the grace period drawing to a close in June this year.
Find out more about Polypipe www.polypipebpfuturehomes.com
