If you’re buying a new-build home in 2026 or considering one, solar panels are increasingly a standard feature rather than an optional upgrade. Regulatory changes over the past few years have transformed new-build energy requirements, and understanding what your developer must provide — and what you should check — could save you thousands.
Part L 2022: What Changed
The updated Building Regulations Part L (conservation of fuel and power), effective from June 2022, requires new homes in England to produce 31% fewer carbon emissions than under the previous standard. In practice, the most cost-effective way for developers to meet this target is solar panels — typically a 3–4kW system on a new 3-bedroom house.
Wales introduced similar requirements through its own Building Regulations amendments, while Scotland updated its Section 6 standards. Northern Ireland follows its own regulations.
The Future Homes Standard
The Future Homes Standard (FHS), phasing in from 2026, dramatically raises the bar: new homes must produce 75–80% fewer carbon emissions than a 2013 baseline. This makes solar panels effectively mandatory on most new builds — a gas boiler alone cannot achieve compliance, and solar is the most practical low-carbon electricity source at building level.
| Standard | Carbon Reduction Required | Solar Typical? | Heat Pump Typical? |
|---|---|---|---|
| Part L 2013 | Baseline | No | No |
| Part L 2022 | 31% reduction | Often | Sometimes |
| Future Homes Standard 2026+ | 75–80% reduction | Yes (almost always) | Yes (most homes) |
What to Expect on a New Build in 2026
A new-build home compliant with FHS should typically include:
- 3–5kW solar panel system (depending on property size)
- Air source heat pump (replacing gas boiler)
- High levels of insulation (walls, loft, floor)
- Triple-glazed or high-performance double-glazed windows
- Mechanical ventilation with heat recovery (MVHR)
- EV charging point (1.4kW minimum under PAS 1899)
Not all developers install batteries — these remain an optional upgrade in most cases, though the gap between generation and consumption on an all-electric new build makes a battery a compelling add-on.
Buyer’s Checklist for New-Build Solar
When purchasing a new-build property with solar, ask your developer or solicitor to confirm:
- MCS certificate: The solar system must be MCS-certified for SEG eligibility. Request a copy before exchange.
- Panel and inverter specifications: Brand, model, warranty documentation, and system size (kWp).
- DNO notification: Confirmation the Distribution Network Operator has been notified (G98 or G99 form).
- Monitoring setup: Login credentials for the inverter monitoring app.
- Ownership: Confirm the panels are owned outright and not on any form of lease or rent-a-roof arrangement (rare on new builds but worth confirming).
- Roof warranty: Does the developer’s roof warranty cover areas with panel mounting?
- Export tariff registration: Some developers register SEG tariffs on buyers’ behalf; others don’t.
New Build vs Retrofit Solar: Key Differences
New-build solar is generally of higher quality and better integrated than retrofit systems — wiring is tidier, inverters are often positioned more accessibly, and the system is designed into the building rather than added as an afterthought. However, panel positioning is sometimes dictated by architectural constraints rather than optimised for generation.
Check your monitoring data in the first few months after moving in — compare against the developer’s stated annual generation estimate to confirm the system is performing as expected.
Frequently Asked Questions
Q: If my new build comes with solar, do I need to do anything to access the SEG?
A: Yes — you need to register for a Smart Export Guarantee tariff with an energy supplier. Your developer may have registered a basic tariff, but you should check and consider switching to a better rate (e.g., Octopus Outgoing at 15p/kWh).
Q: Can I add a battery to new-build solar?
A: Yes — if the inverter is a hybrid model (increasingly common), battery installation is straightforward. If it’s a standard string inverter, you’ll need an AC-coupled battery or inverter replacement. Ask your developer what inverter has been installed.
Q: What happens if my new-build developer hasn’t fitted solar but the planning permission assumed it?
A: Planning conditions sometimes require solar as a condition of consent. If this hasn’t been complied with, the developer may be in breach. Contact your local planning authority — though in practice this is uncommon on FHS-compliant homes.
Q: Are new-build solar systems covered by any builder warranty?
A: NHBC Buildmark warranties (the standard new-build warranty) cover structural issues but typically don’t cover mechanical systems like solar. The panel manufacturer’s warranty and MCS certificate are your primary protections. Check with your developer whether they offer any additional solar warranty.
Q: Do new build solar panels affect my mortgage or stamp duty?
A: No — they’re simply part of the property. A more energy-efficient EPC (typically A or B on a new build) may allow access to green mortgage products from some lenders, offering slightly lower rates.