❌ Solar panels aren’t yet compulsory on new builds

🌞 The 'Sunshine Bill' was rejected by the government in January 2025

🏠 Solar might become mandatory for new developments

⭐ The EU has already made solar panels on new builds a requirement

💷 Many new build properties are ideal for solar panels

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. 

If you're curious about the savings you could get from a solar & battery system, answer a few quick questions below and we'll generate an estimate.

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 who are looking to save the time, effort, and expense of paying the high upfront cost of solar panels.

The energy secretary, Ed Miliband, has said the government will try to make it even more appealing for new-build developers and homebuyers to go solar, but there's been no tangible progress yet.

In July 2024, Miliband said: “I want to unleash a UK solar rooftop revolution. We will encourage builders and homeowners in whatever way we can to deliver this win-win technology to millions of addresses in the UK".

🤔 Thinking of going solar? Here's why a larger system makes sense ⬇️

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

<center><em>Solar panels are currently not compulsory for new build homes</em></center>

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 of switching to solar.

A local community site for Eastbourne has highlighted this exact issue, reporting: "Thousands of new houses are being built in South Wealden without enough solar panels.

"Very similar in Eastbourne where apart from small schemes, houses are being built with either no or inadequate solar.”

The writer adds: "Where they are included, there can be as few as two panels and no battery."

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 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.

However, the government seems to be increasingly doubtful that it can include compulsory solar panels in the new Future Homes and Buildings Standards.

Despite a majority of MPs favouring making it compulsory to install solar panels on new builds, a bill proposing exactly that was rejected by the government in January 2025.

MP Max Wilkinson's so-called 'Sunshine Bill' failed to get the government's support, with housing minister Matthew Pennycook saying that upcoming changes to standards would address the issue more effectively.

Pennycook said the Future Homes and Buildings Standards will “significantly increase rooftop solar deployment”, adding that "introducing conflicting legislation at this stage could create significant confusion".

The government's Future Homes Standard and Future Buildings Standard have been in development since 2019, and haven't yet made it past the consultation stage.

That means the requirements it imposes on homebuilders haven't been agreed upon yet, let alone drawn up, partly thanks to the change of government in July 2024.

Once they are, housing minister Matthew Pennycook has indicated there will be a period of transition, given that "the construction sector typically plans ahead by at least two, if not three or even more, years."

And in October 2024, the Housing Ministry stated: "Solar panels are not currently mandated and it is a fundamental principle of building regulations that we do not constrain innovation by prescribing any specific technology."

The government's 2023 consultation on the Standards suggested two options regarding solar homes: high-efficiency panels covering an area of the roof equal to 40% of the ground floor, or no solar at all.

The first option comes with a caveat: "Although this option is cost-effective at reducing carbon overall, it comes with additional upfront costs for developers and may therefore affect overall housing supply."

This may also indicate a reluctance on the government's behalf towards making solar mandatory for new builds.

<center><em>The UK government rejected the 'Sunshine Bill' in January 2025</em></center>

Are solar panels on new builds mandatory in Europe?

In May 2022, the European Union adopted the Solar Energy Strategy, which makes it compulsory to install solar panels on all new residential buildings by 2029.

The document also states that rooftop solar must be compulsory for all public and commercial properties larger than 250m² by 2027.

Any new buildings that match this description must be directed to install solar panels by 2026.

The Solar Energy Strategy aims to enhance energy efficiency and reduce carbon emissions across the EU.

And some European countries have got a head-start on these plans.

In 2024, France passed a law compelling owners of car parks larger than 1,500m² to install solar panels on their structures.

Car parks over 10,000m² must comply by July 2026, while those between 1,500m² and 10,000m² have until July 2028. 

And in Slovenia, all new buildings with a roof larger than 1,000m² and all new car parks with floorspace that exceeds 1,000m² must have solar panels installed, as of 2024.

How much can new builds save with solar panels?

On average, you could save 86% on your electricity bills with a solar & battery system.

This figure is based on a sample of over 150 systems installed by Sunsave across England and Wales in 2024. The average system is 6.1kWp, with 54% of solar electricity used at home and 46% exported to the grid.

However, solar savings are generally higher than average for new builds, for two main reasons. 

Firstly, putting solar panels on a brand new home tends to be a cheaper process, since it's usually relatively simple to put up scaffolding.

Most new builds are constructed with enough space around the property, in a standard box shape with one consistent roof, which neatly eliminates potential issues like lower roofs, dormers, extensions with flat roofs, and damaged tiles.

Secondly, one consistent roof means ample space for installing solar panels, and a greater number of panels leads to more electricity generation and higher energy bill savings. 

Looking ahead

The current labour government is aiming to build 1.5 million homes in the UK by the end of its term, which will come in Spring 2029. This means 300,000 newly constructed homes every year.

According to the National House Building Council, over 76% of new home registrations in 2023 were for detached, semi-detached, or terraced properties (including 1,466 bungalows). 

Applying the same rate to this Labour government's 1.5 million new builds, we can assume about 1.14 million of them will be suitable for solar. This represents a massive opportunity to transform energy bills for a vast number of households. 

However, until meaningful legislation is put in place, 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. 

If you're thinking of switching to solar and want to find out how much you could save with a solar & battery system, enter a few details below and we’ll generate an estimate for you. 

Solar panels on new builds: FAQs

Do new builds require solar panels?

Should new builds have solar panels?

When will solar panels become mandatory for new builds?

Who owns solar panels on new builds?

Do solar panels increase home value?

Do solar panels invalidate NHBC?

Solar panels on new builds: what are the rules? [UK, 2025]

What's in this guide?

Solar panels on new builds: what are the rules?

✅ The MCS certificate is one of the best stamps of approval for green technology 

☀️ It covers both solar panels and solar panel installers

➕ There are many benefits to have a certified solar panel installation

📃 It’s not mandatory to have an MCS certificate, but your system should be certified

❌ Be wary of solar panel installers that aren't certified

The world of solar panels is awash with technical terms and acronyms, and one you’ll come across a lot is MCS, or the Microgeneration Certification Scheme. 

While lots of solar panel jargon is not essential for you to know before you get a solar & battery system, it’s definitely worth knowing a bit about the MCS - particularly when it comes to choosing a reliable solar company.

Along with Flexi-Orb, it's one of the two top certification schemes for solar installers and products.

To find out how much a certified solar & battery installation could save you on your energy bills, answer a few quick questions below and we'll provide you with an estimate. 

What is the MCS certificate for solar panels?

The Microgeneration Certification Scheme (MCS) is a government-backed UK initiative that was set up in 2007 to make sure small-scale renewable energy installations, like solar panels and heat pumps, meet universal quality standards.

This came at a very important time for the solar panel industry in the UK, as it wasn’t long before the Feed-in Tariff suddenly fired up demand for solar across the nation. And given the fairly high upfront cost of solar panels, it makes sense that solar installations need to meet a certain level of quality. 

There are MCS certifications available for solar panels and installers, which when combined should mean your installation goes smoothly. You should also look for products and specialists with a Flexi-Orb certification, which will ensure the same high standards.

It's vital that your solar panel system and installer have an MCS or Flexi-Orb certificate, as this is the only way to make sure they'll work to the high standard you deserve.

If an installer has one of these certifications, it means they’ve met a whole host of rigorous requirements, ranging from technical skills (under the MCS 001 and Solar PV-specific Standards) to their competency in running a reputable business.

Either certificate is a seal of approval that shows consumers that a product a) is safe, b) will work as it should, and c) is built to last.

Like Flexi-Orb, MCS has created Product Standards that include a lengthy list of testing and performance criteria, checks panels have regulatory safety marks, and ensures manufacturers carry out regular audits.

When speaking to solar panel installers, be sure to ask them if they're certified by MCS or Flexi-Orb - along with these six other important questions. 

What are the benefits of having an MCS certificate?

If your domestic solar & battery installation has an MCS certificate, it means you’ll experience the following advantages: 

Access to most smart export tariffs, potentially worth around £360 per year*

Fewer malfunctions and issues with your system

Higher output due to efficient, quality hardware, leading to more savings

Increased property value through professional installation

*Based on a home using 3,400kWh of electricity per year (which is the UK average) with solar irradiance of 850kWh/kWp, a 4.4kWp solar PV system, and a 5.2kWh battery. The home is signed up to E.ON’s Next Export Exclusive for export, E.ON Next Drive Fixed V5 for import, and exports 65% of its solar electricity.

The UK's first solar subscription

Is it mandatory for your solar panels to have an MCS certificate?

It's not strictly mandatory for your solar panels to come with MCS or Flexi-Orb certification, but it's highly recommended, especially if you want to take advantage of certain financial incentives.

Having an MCS or Flexi-Orb certificate opens doors to export tariff schemes like the Smart Export Guarantee (SEG), which allows you to get paid for sending surplus electricity to the grid.

Export tariffs tend to have strict requirements, one of which is MCS or Flexi-Orb certification.

Suppliers may eventually relax this rule to include other certifications, but they will always want to ensure your installation was fitted to a high standard before signing a contract.

How can you verify that your solar installer is MCS certified?

Checking if your solar installer is MCS certified is pretty straightforward. The MCS website has a handy database where you can search for certified installers by their name and location – just pop in their details and the site will confirm if they're registered, as well as their unique Certification Number. 

How do you get your MCS certificate for your solar panels?

Your installer usually takes care of getting an MCS certificate for your solar panels during the installation. But to be eligible for an MCS certificate, your solar panel installation must first:

Be commissioned by an MCS-certified installer

Have a commissioning date after 15 July 2009

Your installer should issue your MCS certificate within 10 working days of wrapping things up. A good solar panel installer will give you an MCS certificate automatically – but it's always a good idea to double-check at the beginning.

There are only two situations where you can get a copy of your certificate directly from MCS: if the installer isn’t MCS certified anymore or they stop trading. In these cases, you’ll need to pay an administration fee and provide proof of ownership for your solar panel system – if not, you’ll have to go back to your installer to ask for your certificate.

If you decide to cut costs and buy used solar panels, you'll have to install the panels yourself (which we do not recommend, due to safety risks) and you won't be able to get your system certified by MCS or Flexi-Orb. 

Is the MCS certificate easy for installers to get?

You’ll be glad to know that getting an MCS certificate isn't a simple tick-box exercise for solar panel installers – it requires them to meet a set of strict standards. Here's a brief breakdown of what’s needed:

Getting assessed: Installers need to know and show they understand both parts of the MCS 001 Standard and the technical standards for solar PV technology.


Competency criteria: The installation company needs to prove they have skilled employees who meet the MCS 025 Standard. This involves identifying a Nominated Technical Person (NTP) who has completed an MCS approved training course for solar PV technology.


Processes and procedures: Installers should have evidence of an appropriate Quality Management System (QMS) in place to handle installation quality.


Consumer Code membership: Installers have to join a Consumer Code approved by the Chartered Trading Standards Institute (CTSI), like the Renewable Energy Consumer Code (RECC) or the Home Insulation & Energy Systems Quality Assured Contractors Scheme (HIES).


Applying to a Certification Body: Finally, installers apply to a Certification Body to assess and inspect their company practices.

As you can see, the MCS certification process for installers is thorough. An MCS-certified installer has to be dedicated and put in effort for each step to maintain a high standard.

Can I trust installers who don't have an MCS certificate?

Installers without an MCS certificate are still well worth using if they have a Flexi-Orb certificate instead.

In fact, a Flexi-Orb certification actually indicates a higher level of quality in many ways. 

For instance, Flexi-Orb’s Installation Scheme has stricter requirements, meaning it requires much more effort from installers to get certified.

This continues after the assessment as well, as Flexi-Orb’s certification bodies keep evaluating installers once they’ve been certified, to ensure they maintain their standards.

Customers are also protected by an insurance-backed guarantee, plus they can leave reviews that will be available to all customers looking for a renewable installation.

But if an installer hasn't been certified by MCS or Flexi-Orb, they're not worth hiring.

Some of these installers will still produce high-quality work, but the risk is too large for any homeowner to take.

You also wouldn't be eligible for an export tariff, which could cost you hundreds of pounds per year.

What are the risks of not using an MCS-certified installer?

The risks of not using an installer who's been certified by MCS or Flexi-Orb include:

Not being eligible for financial perks like an export tariff

The potential risk of poor installation or subpar product quality, which would affect efficiency, output, and savings

Manufacturer warranties might require installation by certified professionals

Shoddy work may affect your property's market appeal and value

How many solar installers are MCS certified?

As of January 2024, the MCS has certified more than 3,300 solar installers – with 1,300 of these certified in 2023 alone, marking a 65% increase from the previous year. 

What other solar accreditations are important?

In the UK, there are a few other crucial solar accreditations and membership associations for installers, apart from the MCS and Flexi-Orb. These include:

The Renewable Energy Assurance Limited (REAL) scheme

National Inspection Council for Electrical Installation Contracting (NICEIC)

National Association of Professional Inspectors (NAPIT)

Home Insulation and Energy Systems Quality Assured Contractors Scheme (HIES)

These accreditations help ensure that installers are qualified, follow best practices, and provide work with certain levels of guarantee or warranty. 

Summary

If you're considering installing solar panels on your home or business, hiring an installer who's been certified by MCS or Flexi-Orb is an important step to ensuring the quality and safety of your system.

To find out how much a certified solar & battery system could save you on your energy bills, provide us with a few quick details below and we'll get back to you with an estimate.

MCS certificate for solar: FAQs

Do you need an MCS certificate for solar panels?

How do I get an MCS certificate?

How much does MCS certification cost?

Here's why the Microgeneration Certification Scheme is one of the best ways to guarantee your solar installation's quality.

The MCS certificate for solar panels: an expert guide [2025]

The MCS certificate for solar panels: an expert guide

⚡ Solar cells are able to create electricity because they contain an electric field

☀️ Photons dislodge electrons, generating an electric current

🏠 Your inverter converts DC electricity to AC electricity you can use in your home

🔋 Any excess solar electricity goes to your battery or the grid

🌧️ Solar panels work well everywhere in the world, even in the rainy UK

From baking hot deserts through cloudy countries to outer space, solar panels are a powerful tool for helping us convert sunlight into electricity and combat climate change. 

This guide will take you through the key steps of how solar panels work, from the initial capture of light to the powering of your home.

If you're interested in finding out how much money a solar & battery system can save you, just answer a few quick questions below and we'll provide an estimate.

How solar panels work: step by step

Below, we’ll take a closer look at each of the five key phases of how light from the sun leads to savings on your energy bills. 

Any excess goes to your battery / the grid

1. Solar cells are given an electric charge

Solar or photovoltaic (PV) cells are the building blocks of solar panels. Each PV cell is formed of two slices of semiconducting material - this is most commonly silicon, but scientists are also testing newer materials like perovskite and kesterite.

PV cells are able to generate electricity because they contain an electric field, which is created when opposite ‘charges’ are separated. To create it, manufacturers ‘dope’ the two layers of silicon with different materials. 

The top layer of the cell is infused with phosphorus to add extra electrons, and this gives the layer a negative charge. Conversely, the bottom layer is laced with boron, giving it fewer electrons and a positive charge.

When these two layers are sandwiched together, an electric field forms between them. This setup ensures that when light excites electrons in the silicon, they are directed into an external circuit, creating a flow of electricity.

2. Light from the sun hits the solar panel

Light is composed of many photons, which are essentially tiny packets of energy.

Each silicon atom in the solar cell has 14 electrons, but only the outer four, called valence electrons, are involved in the photovoltaic effect. And given that just a gram of silicon contains about 21.4 quadrillion atoms, there are plenty of valence electrons available for this process.

When photons hit the solar cell, they transfer their energy to the valence electrons in the silicon atoms. This energy boost is enough to knock the electrons out of their atomic bonds, freeing them to move around. The electric field between the two layers of silicon then pushes the free electrons out, creating an electric current.

Silicon solar panels in today's market are designed to absorb light primarily in the visible spectrum, but they can also capture light in the infrared and ultraviolet ranges. This means that a solar cell doesn't depend on direct sunlight - daylight is enough to trigger the photovoltaic effect. 

But not all the light that hits the solar panel gets converted into electricity. Monocrystalline solar panels typically have an efficiency range of 18% to 24%, so a lot of the light energy is wasted, either as a reflection or lost as heat.

People think that you need perfectly sunny weather to make solar panels worthwhile, but this isn’t the case - all solar panels need in order to generate electricity is daylight, not sunlight. There are many other factors beyond location that have an impact on generation, including roof size, pitch, orientation and shading.

Once photons set the electrons loose in a solar cell, metal contacts on the edges of the cell collect the freed electrons and transfer them to the wires. This movement of electrons creates direct current (DC) electricity, which is then sent to an inverter. 

DC electricity flows in a single direction and provides a constant voltage, but it doesn't travel well. In contrast, alternating current (AC) electricity changes direction periodically, typically 50 times per second (50 Hz) in the UK.

AC is the best choice for homes because it's more efficient for sending power over long distances and works with both the electrical grid and most household appliances, lights, and other electrical devices.

The inverter uses transistors to make the DC electricity act in the same way as AC electricity, and then sends it through a transformer. In essence, the transformer is basically conned into thinking that the DC electricity is AC electricity, and so produces AC electricity at the other end. The inverter basically contains a very successful partnership built on deception.

The end result is AC electricity that matches the voltage and frequency of your home's electrical system, and you can use it right away for your appliances, lights, and other devices.

As solar panel output peaks in the middle of the day, that's the ideal time to focus most of your electricity usage. If you’re not at home to do this, you can use smart apps and plugs to schedule when various devices turn on.

5. Any excess goes to your battery or the grid

Wondering how solar panels produce electricity? We look at the science behind the photovoltaic effect and explain how the electricity reaches your home.

Melody Abeni

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