Get on top of the Part L challenge


Changes to Part L of the Building Regulations are planned to come into effect later this year as part of the Future Homes Standard, meaning a 31% reduction in new build carbon emissions. Stuart Nicholson of Marley explores why the inclusion of solar PV roofing could be a key solution.

With the climate emergency once again having been highlighted at COP26 in Glasgow, the UK’s Net Zero Strategy – to be achieved by 2050 – is now beginning its transformation from plans, policies, and aspiration into an everyday reality that will influence and impact the way we live, move around, connect and work.  

According to the Government’s Climate Change Committee, the built environment accounts for around 40% of UK greenhouse gas emissions, with approximately 14% of this coming from the 28 million homes in the UK. As a major contributor to carbon emission damage, the role of households, and the need to make the nation’s housing stock more energy efficient, is central to the Net Zero Strategy, and that puts the future construction of sustainable new homes front and centre.

As part of the move towards the creation of more energy efficient homes, 2022 sees changes implemented to Part L of the Building Regulations. They come into force (with a one-year transition period where the old Part L rules can still be followed) with the primary objective to direct the construction of new homes so they produce 31% lower carbon emissions.  

The Part L changes are among a raft of other amendments in preparation for the introduction of the Future Homes Standard in 2025. From that point, housebuilders and developers will be required to ensure all new homes are specified and constructed to be highly energy efficient, use low carbon heating solutions, and, ultimately, be ‘zero carbon ready.’ 

As a result, housebuilding teams, along with architects and specifiers, need to design sustainably and seek out the product solutions that will allow them to meet the robust carbon emission targets the sector is now faced with. The decisions currently being taken, as well as those over the coming months and years, will help to define future achievement and the housebuilding industry needs to be fully acquainted with the range of sustainable product answers it can access today.


Improvement in new home energy efficiency – and resulting lower carbon emissions – cannot simply be delivered by enhancing the building fabric alone. 

It is widely anticipated the specification of solar PV, with an efficient gas boiler or a heat pump, will be the route favoured by housebuilders to achieve the required levels stipulated by Part L for this year.

Housebuilders need to recognise that, in the short term, solar PV on the roof – combined with an efficient gas boiler – appears to be the most time efficient and cost-effective way for the sector to meet the new 2022 Part L carbon reduction obligations. This is in part because some will already have a supply chain and trusted installers in place to enable an increase in specification to be implemented.


While many in the sector may have had prevailing concerns about the aesthetic appearance of solar PV, innovative advances in both the look and performance of solar PV means legacy concerns can be overcome.

The latest and fully integrated solar PV roof systems offer a more visually appealing, cost effective, and easier to install option. The integration benefit means solar panels can simply replace a section of existing roof tiles to create a sleek aesthetic, and deliver a seamless solution as part of the overall roof visual appeal. This type of integrated solar panel can also be installed at the same time as the roof tiles and dovetail with the busy build schedules on development sites.

Solar PV technology is tried and tested, readily available and has become much more affordable in recent times, making it a highly attractive solution ahead of the imminent Part L changes. Solar Energy UK predicts the modification to Part L could lead to a five-fold increase in the number of new homes built with solar technology as part of long-term sustainable construction strategies. This demand is expected to be maintained during the coming years as gas boiler installation in new homes is phased out to meet the new 2025 Future Homes Standard.  

At this point, the specification of heat pumps is predicted to become the sustainable heating solution of choice on new builds as housebuilders are obligated to meet the requirements of the new standard. Again, the combination of low carbon heat pumps together with solar PV on the roof will help drive the energy efficiencies and the carbon cutting success the Government and homeowners want to see. 

In addition, during a period of escalating energy prices that could affect all households for the foreseeable future, solar PV will play its part in minimising high energy running costs for buyers of new homes and sustainably support changing household requirements such as increased demand for charging points for electric vehicles.  


As a new, sustainable housebuilding era begins to emerge as both the Part L changes and the forthcoming Future Homes Standard impact the market, the environmental and low carbon performance of buildings will become a top priority for housebuilders and developers.  

Critically, this is now the time for the sector to engage with and work alongside sustainable product manufacturers – including those delivering integrated solar PV solutions – to better understand product innovation, while also tapping into the technical expertise they can offer to provide operational and commercial benefits.

Informed choices will help to define future success for the construction and roofing sector. Taking advantage of the current technical expertise, product solutions, and project support on offer from manufacturers can support housebuilders as they strive to deliver the energy efficient and low carbon homes the nation will require in the future.

Stuart Nicholson is roof systems director at Marley