Ramin Hakimov, Head of Commercial & Policy Engagement at Allume Energy UK, which develops solar sharing technology for multi-residential buildings, looks at what the new solar requirements in the Future Homes Standard mean for planners, and why apartment buildings must not be left behind.
The summer’s record-breaking temperatures highlighted just how ill-prepared many of our homes are for a changing climate. As extreme weather events become more frequent and severe, ensuring our housing stock is resilient has become an increasingly pressing challenge, and one the Future Homes Standard (FHS) seeks to address.
The FHS comes into force on 24 March 2027, but its influence is already being felt across the industry. With the Approved Documents published in March 2026, developers, planners and design teams are already working on schemes that will need to comply with the new requirements.
For planners, the changes will fundamentally influence how future developments are designed and assessed. Schemes entering the design stage today are likely to be delivered under the Standard, making early design decisions more important than ever.
Much has been written about what the Future Homes Standard means for building fabric, heating systems and operational carbon. Far less attention has been given to the new solar requirements, and almost none to the challenge of delivering meaningful rooftop solar for flats, despite apartments accounting for a significant proportion of the new homes the government intends to build.
A changing regulatory landscape
The updated Building Regulations introduce significantly higher performance standards for new homes, requiring substantial reductions in operational carbon emissions compared with previous standards. Alongside these changes, a new functional requirement for on-site renewable electricity generation means rooftop solar will become the default solution for most new homes in England, subject to recognised technical exceptions.
In practice, this represents one of the most significant changes to residential design in decades.
The benchmark assumes solar panel coverage equivalent to approximately 40% of the dwelling’s ground floor area, using panels rated at around 0.22 kWp per square metre, whilst also taking account of orientation, roof pitch and shading.
Two points are particularly important:
- Firstly, compliance continues to be demonstrated using SAP 10.3 during the transition period, before the Home Energy Model (HEM) is introduced.
- Secondly, and perhaps more significantly, solar has become a functional requirement in its own right rather than simply another tradeable design element. In practical terms, this means it cannot simply be designed out by improving performance elsewhere.
The fabric-first approach remains absolutely the right starting point, and improvements to insulation and airtightness are welcome. However, planners and design teams who assume the required carbon reductions can be achieved through fabric improvements and heat pumps alone, before considering solar as an afterthought, are likely to find themselves revisiting schemes later in the design process.
Four key FHS considerations for planners
1. Solar shouldn’t be an afterthought
Roof design, orientation and massing should be considered alongside solar generation from the earliest design stages.
On terraced developments and courtyard schemes, for example, the street layout that creates the strongest urban design outcome may not necessarily maximise solar generation. These trade-offs are best resolved during masterplanning rather than after planning applications have progressed.
Bringing photovoltaic design into the process early allows the available roof area and generation potential to inform the overall scheme before layouts become fixed.
2. Understanding what happens when the benchmark cannot be achieved
The regulations recognise that the benchmark will not always be achievable.
Where roof configuration, orientation or shading genuinely prevents full compliance, a reduced array may be accepted, provided the constraints are clearly evidenced through robust technical assessment and roof design.
This introduces an additional layer of technical justification, particularly on higher-density urban developments where roof space is constrained by plant equipment, access requirements and building form.
As the industry gains experience of implementing the Future Homes Standard, the practical application of these exceptions will become increasingly important.
3. Solving the apartment challenge
Apartment buildings represent one of the biggest challenges and opportunities within the Future Homes Standard.
Historically, the UK’s traditional “one roof, one meter” approach has made rooftop solar on multi-residential buildings commercially and technically difficult. Developers have typically been left with two choices: divide limited roof space into multiple small arrays serving individual dwellings, or connect the system solely to landlord supplies.
The latter remains common, meaning rooftop solar often offsets communal electricity consumption whilst residents continue paying full retail electricity prices for their own homes.
As a result, whilst around 7% of UK houses benefit from rooftop solar, only around 3% of flats do, with adoption considerably lower in many dense urban locations. Given that millions of people across England and Wales live in flats, many of whom are social housing residents or households facing higher energy costs, this disparity has significant social as well as environmental implications.
The challenge becomes even greater as buildings increase in height. Roof area available per dwelling reduces significantly with every additional storey, before allowing for plant, maintenance access and fire safety requirements.
The regulations acknowledge some of these practical constraints, including separate implementation arrangements for higher-risk residential buildings.
However, if the Future Homes Standard succeeds in driving rooftop solar on houses whilst apartment residents continue to receive little direct benefit, we risk widening an existing inequality in access to clean, affordable energy.
4. Viability and cost
The government’s impact assessment estimates an average construction cost increase of approximately £4,350 per dwelling across heating, solar, ventilation and fabric improvements.
For developers, local authorities and housing associations, these additional costs will inevitably influence viability assessments, procurement strategies and delivery programmes.
Rather than waiting until 2027, those conversations should already be taking place.
Technology is now catching up with regulation and is starting to address many of the challenges that have historically prevented rooftop solar from benefiting apartment residents.
Allume’s SolShare technology enables electricity generated by a single rooftop solar array to be dynamically shared between individual apartments while allowing each resident to retain their own electricity supplier.
The system requires one rooftop array and one grid connection, with no additional equipment installed inside individual flats. Today, SolShare has been installed across more than 4,000 homes throughout the UK. At Odet Court in Cardiff, for example, residents are saving up to £690 per year through a shared solar and battery system.
Shared rooftop solar is not the answer for every building. Where roof space is extremely limited or heavily shaded, the benefits may understandably be constrained.
However, for many apartment developments, technologies that enable shared access to rooftop solar provide a practical way of ensuring residents living in flats can benefit from the same clean energy opportunities as those living in houses.
The Future Homes Standard should not simply be viewed as another compliance exercise.
It represents an opportunity to rethink how we design homes that are not only lower carbon, but also cheaper to run and more resilient for the people who live in them.
The decisions being made by planners, developers and design teams today will shape the performance of our homes for decades to come. If we can ensure apartment residents benefit from rooftop solar alongside those living in houses, the Future Homes Standard has the potential to deliver not only better buildings, but fairer energy outcomes too.
