Blog by Solar Energy UK member Josh King, Gensource
Josh King examines Scotland’s impressive record in leading the way for energy-efficient building regulations. Having championed solar power generation in new homes since 2015, Scotland now faces an unexpected hurdle. The blog looks at recent policy changes and upcoming standards that might unintentionally sideline solar energy.
A brief history of building standards and energy
The way in which buildings are designed and constructed has been evolved over millennia, with possibly the first example of a ‘building standard’ around 4,000 years ago in Babylon, Mesopotamia,
“If a builder builds a house for a man and does not make its construction firm, and the house which he has built collapses and causes the death of the owner of the house, that builder shall be put to death.”
That certainly makes current building control seem tame! Since then the standards to which buildings are built have gradually evolved. This has usually been a tussle between private and public interests and often thrust forward by crises. For example, the great fire of London in 1666 wiped out around 80% of the city’s buildings, leading to The London Building Act in 1667, laying out clear terms for building safety.
Scotland charging ahead
Scotland officially led the way as the first UK nation to adopt national building regulations in 1963. Even this iteration included energy performance in the form of thermal efficiency of buildings.
Fast forward to today and Scotland continues to lead. The 2015 uplift to the building regulations were miles ahead of the rest of the UK in terms of energy performance. They introduced the ability to meet the target carbon emissions rate (TER) by adding solar generation.
You can find a comprehensive overview of this at The Solar Blogger
Scotland’s share of solar powered homes continued to grow from 9% in 2015 to almost 70% in 2020. However, could this be the peak for solar powered homes in Scotland?
Scotland’s own Solar-Coaster!
In recent years the intersection of two key policy changes, stand to erase any requirement for solar on new Scottish buildings.
On 1st April 2024, the New Build Heat Standard (NBHS) came into effect. The primary outcome of which is that no new homes will be built with direct emission heating systems (DEHS), which includes gas boilers, biomass etc.
Whilst this policy on its own has been widely praised as Scotland continuing to lead on climate and energy, it is inevitably going to lead to the mass adoption of heat pumps. The 2021 changes in the building regulations means that homes heated with heat pumps can meet the standards with no solar. So, without any uplift in regs to encourage solar on our zero-direct-emission-heated homes, there may be a cliff edge for solar on new buildings.
Scottish Passivhaus
If industry weren’t already kept on their toes awaiting the implementation of the above changes, there came another climate curing curveball.
On January 10th, 2023, the Scottish Government announced plans to adopt a Scottish equivalent to Passivhaus. This was spearheaded by a private members bill by Labour MSP Alex Rowley, and announced by Green Minister, Patric Harvie.
As a brief overview, Passivhaus is an extremely rigorous design standard aimed at making buildings so well insulated and ventilated, that they hardly require any additional heating or cooling (hence, passive).
But, Scotland has not committed to building to Passivhaus standard by 2025, only to have legislated a Scottish equivalent.
What does Scottish Passivhaus Equivalent Mean?
Well there is a lot of work going on behind the scenes to answer this. The Government is planning on a public consultation this summer. On one hand Passivhaus is such a drastic change to standards we currently build to, that there seems to be so much work yet to do. On the other hand, since the definition of ‘equivalent’ is seemingly entirely up for grabs, we could find ourselves seeing a completely diluted version of Passivhaus standards implemented.
Currently there are calls from construction industry to dial back or scrap the plans, and the Passivhaus trust who are pushing heavily for full adoption of the standard, are even recommending that the Scottish Government allow time for industry to upskill and prepare. It is unlikely any new regs will crash land in January.
A typical Passivhaus would not necessitate solar and that would be divergence from Scotland’s neighbours.
What’s happening elsewhere?
England has recently closed its consultation on the Future Homes Standard. This proposes to completely change the way that energy performance is designed and modelled in new buildings. The consultation proposes banning gas boilers (following Scotland’s lead) and is seeking views on how much is solar to required on a low carbon heated home.
In Europe on the other hand, the whole of the EU have seen the light and are committed to building solar powered buildings. The EU Solar standard, agreed in March 2024, will require solar on all new and commercial and public buildings by 2026 and all new residential buildings by 2029.
As Scotland has precedence of both progressive energy policies and also aligning itself with EU, it would be a real shame not to align itself with a commitment to solar powered buildings.
Why solar powered buildings?
Solar powered buildings deliver energy at the point of use. For the consumer, they lower the energy demand of the home, reduce carbon emissions, and lower running costs. Shifting our new homes onto electric heat and transport stand to increase running costs without the addition of solar.
On a wider, electrified homes, heat and transport is only zero-carbon if the grid is zero carbon. Solar powered buildings deliver this clean energy at the point of demand. This provides a decarbonised and better utilised electricity system. As a nation it brings us closer to our net zero goals.
So will Scotland’s future homes generate energy?
Well, this is a difficult question to answer, not least because since starting to prep this article, The Scottish government has rescinded its 2030 carbon targets and the SNP ended their coalition with the Greens, and minutes before writing this sentence the Scottish First Minister resigned. There’s going to be a lot of uncertainty about how many climate commitments are kept and our leading building standards could be at risk.
What we need now from Scottish Government and incoming First Minister is to firmly maintain Scotland’s climate leading commitments, including a 4-6GW ambition for solar, and commit to a long-term stable policy ambition for solar powered homes and buildings.
About the author Gensource
Gensource specialises in sustainable energy solutions, providing a range of services such as solar power systems and electric vehicle charging infrastructure. Their dedicated team prioritises reliability and innovation, delivering tailored solutions to meet clients’ needs. Gensource leads the charge towards a greener future.