New-build homes and solar panels are increasingly inseparable — and for good reason. The UK’s Future Homes Standard, evolving Part L Building Regulations, and the broader push toward net-zero housing have made solar a standard specification on many new developments. Whether you’re a developer planning a scheme, a buyer considering a new-build with solar, or a new-build owner wanting to understand or upgrade your existing system, here’s what you need to know.
Are Solar Panels Required on New-Build Homes & Developments?
Solar panels are not yet a universal legal requirement on all new-build homes and developments in England, but the direction of travel is clear. The updated Part L of the Building Regulations (effective since June 2022) significantly tightened energy efficiency standards for new homes, and solar panels are one of the most straightforward ways developers meet the required carbon reduction targets.
Under Part L 2021, new homes must achieve a 31% improvement in carbon emissions compared to the 2013 baseline. For most new-build designs, solar PV is the most cost-effective way to hit this target while still using gas boilers or heat pumps — which is why panels now appear on the vast majority of new residential developments.
The forthcoming Future Homes Standard, expected to be fully implemented by 2025–2026, will push requirements further, effectively mandating low-carbon heating and significantly higher fabric standards. Solar is expected to be a near-universal feature of compliant new builds under this framework.
What Solar Systems Are Typically Installed on New Builds?
Developer-installed solar systems on new builds tend to be:
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Smaller than optimally sized — Often 2–4kWp, sufficient to meet Part L compliance but not necessarily sized to the homeowner’s actual energy needs
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Integrated into roof tiles — Some developers use integrated solar tiles (such as those from Marley Eternit or similar manufacturers) for aesthetic reasons
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Without battery storage — Most new-build solar installations are solar-only; battery storage is rarely included in the base specification
This means many new-build buyers are living in a solar-equipped home without getting the maximum financial benefit from it — because the system isn’t large enough or isn’t paired with storage.
Should You Upgrade a New-Build Solar System?
If your new-build came with a solar system, it’s worth reviewing whether:
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The system is appropriately sized for your actual household consumption
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Battery storage could be added to increase self-consumption
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The inverter is compatible with battery retrofit
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The system has been correctly commissioned and registered for SEG payments
HomeKog can assess your existing new-build solar installation and advise on whether a battery addition or system expansion would deliver meaningful additional savings.
What Should New-Build Buyers Look For in a Solar Specification?
When reviewing a new-build’s solar specification, ask the developer:
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What is the rated capacity of the system (kWp)?
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Which brand and model of panels and inverter are installed?
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Is the system MCS-certified?
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Has the property been registered for the Smart Export Guarantee?
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Is the inverter battery-compatible for future retrofit?
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What monitoring system is included?
A developer who can’t answer these questions clearly should prompt caution.
Can Developers Benefit From Installing Solar Across a Full Development?
Yes, significantly. For volume housebuilders:
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Solar helps satisfy Part L and Future Homes Standard compliance efficiently
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It reduces the need for expensive fabric upgrades by offsetting operational carbon
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It improves EPC ratings across the development, which affects mortgage accessibility for buyers
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It can be specified as a differentiator in marketing and improve sales conversion
Bulk installation pricing makes per-unit costs considerably lower than individual residential installations.
The Part Nobody Talks About: The New-Build Solar Gap
There’s a common frustration among new-build buyers that often goes unspoken: the solar system on the roof of their new home isn’t delivering what they expected. This happens because developer-installed systems are designed to satisfy Building Regulations — not to maximise the homeowner’s financial return.
A 2.5kWp system on a south-facing new-build roof generates around 2,000–2,200 kWh per year. A household of four with an EV and average appliance use might consume 7,000+ kWh. The solar system covers perhaps 20–25% of that. Adding battery storage and expanding to 6kWp could push that self-sufficiency figure to 50–60%.
The gap between “regulatory compliance solar” and “properly designed solar” is significant — and it’s one of the most common upgrade conversations HomeKog has with new-build owners.
Frequently Asked Questions
Q: Does the solar system installed by a developer come with a warranty?
Yes, developer-installed solar systems should come with panel performance warranties (typically 25 years), product warranties (typically 10–12 years), and installation workmanship warranties. The documentation for these should be included in your new-build completion pack. If it isn’t, request it — you’ll need it for SEG registration and any future sale.
Q: Can I add more panels to a new-build roof that already has solar?
In most cases, yes. Adding panels to an existing new-build system is possible subject to roof space, inverter capacity, and DNO notification. The main consideration is whether the existing inverter can handle the additional capacity or needs upgrading. HomeKog can survey your roof and existing system to advise on the most cost-effective expansion.
Q: Are solar tiles on new builds as effective as standard panels?
Solar roof tiles generate electricity in the same way as standard panels, but typically at lower efficiency per square metre. They integrate more seamlessly with the roof aesthetics, which is why some developers specify them, but they usually generate less than an equivalent area of standard panels. If maximum generation is the priority, standard panels typically offer better value.
