Solar panels on new builds: what are the rules?

There is a desperate need for more housing in the UK right now, and - in the face of high energy bills - a similarly desperate need for green energy. 

It would make sense to kill two birds with one stone and ensure that all newly built homes in the UK have solar panel systems, but is this actually what’s happening right now?

In this article, we’ll explore the UK’s current approach to solar panels on new builds, consider what needs to change, and see how countries are tackling the issue in the EU. 

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Are solar panels on new builds compulsory?

Unfortunately, solar panels aren't compulsory on new builds, but they have become a common way for developers to meet certain building regulations and make developments more sustainable. 

Many construction companies choose to install them in order to meet the required SAP (Standard Assessment Procedure) score for energy efficiency. 

By incorporating solar panels, developers enhance the property's energy performance, and also make it more attractive to eco-conscious buyers looking to save time and effort on forking out the high upfront cost of solar panels.

What is a building’s SAP score?

Introduced by the UK government in 1992, a building's SAP score is a calculation of its energy cost performance using criteria like insulation, heating, lighting, and renewable energy sources. Each building’s SAP score is also used to determine its Energy Performance Certificate (EPC) rating. 

SAP scores are given on a scale of 1 to 100+, with higher scores indicating better energy efficiency and less environmental impact. A score of over 100 would mean that the property’s net cost of energy over the year is £0, and is instead being paid (for example through solar export tariffs).

There isn't a specific minimum SAP score for new builds, but homes with poor SAP scores and low EPC ratings are likely to be more difficult to sell. According to the UK Government's most recent English Housing Survey in 2021, the average SAP rating was 66 points.

Here are some measures developers can take to improve the SAP score for new builds:

• Ensuring walls, roofs, and floors are well-insulated to reduce heat loss
• Installing high-efficiency boilers or heat pumps
• Adding solar panel systems to generate renewable energy
• Using double- or triple-glazed windows with low U-values
• Incorporating LED lighting throughout the property
• Installing mechanical ventilation with heat recovery (MVHR) systems
• Minimising thermal bridging through careful design and construction practices
• Implementing smart thermostats and heating controls to optimise energy use

How do solar panels help with a property’s SAP score?

Solar panels are an effective choice for companies building new properties as they help reduce energy costs, which is a key factor in the calculation of an SAP score.

However, the specific number of SAP points that a solar panel system contributes depends on the system's size and other aspects of the property, such as insulation, heating efficiency, and overall energy demand.

The current problem with solar panels on new builds

Even though installing solar panels on new builds is a great way to set new homes up with renewable energy from day one, it’s not yet a legal requirement. 

One common problem is that developers don't use all the available roof space, resulting in a less effective solar panel system. The property achieves a higher SAP score because it has a few panels, but the actual impact on energy bills is negligible. 

This can then create logistical challenges if the homeowner later decides to expand their solar panel system. Often, the original panels need to be removed in order to accommodate a larger system, which adds to the total cost.

Will solar panels on new builds become compulsory?

The support for solar panels to become compulsory on new builds is growing. A Censuswide survey in February 2024 showed that 70% of UK adults support mandatory solar panels on newly built homes, and nearly half of those surveyed plan to install solar within the next five years.

A recent YouGov poll of 107 MPs in January 2024 revealed that 79% of them advocate for the inclusion of solar panels in all new constructions by 2025, signalling a push for further environmentally-friendly building regulations.

Following a consultation by the UK Government, Solar Energy UK predicts that compulsory solar panels will be included in the upcoming Future Homes Standard and Future Buildings Standard (due for publication in late 2024).

Are solar panels on new builds mandatory in Europe?

In March 2024, the European Parliament approved a law requiring solar panels on all new residential buildings by 2030. The EU Solar Standard makes it mandatory for member states to gradually include solar installations in new public, commercial, and residential buildings.

The directive aims to enhance energy efficiency and reduce carbon emissions across the EU. The law will be rolled out slowly, first for public and commercial buildings by 2026, and then for all new residential buildings by 2030.

Summary

The benefit of legally mandated solar panels on new builds in the UK would be enormous, and it seems to be on the horizon. However, until that time, it’s crucial that developers refrain from putting a pointlessly small number of solar panels on the roofs of new properties, as this only causes headaches for homeowners further down the line. 

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Solar panels on new builds: FAQs