Do all new builds come with solar panels?

Not all, but an increasing majority. Since June 2022, Part L Building Regulations in England require significant carbon reductions in new homes. Solar panels are the most common compliance method. Scotland and Wales have similar requirements.

Is the solar system on a new build free?

The cost is included in the house price — you are not charged separately. However, the system is typically the minimum size needed for regulatory compliance (1–2kW), not the optimal size for maximum savings (4–5kW).

Can I add more solar panels to a new build?

Yes. You can expand the system by adding panels to existing rails (if the inverter has capacity) or by installing a second independent system. The cheapest option is to request a larger system as a developer upgrade before moving in.

Who is responsible for maintaining solar panels on a new build?

You are, once you complete the purchase. The developer's warranty typically covers defects for 2 years (NHBC Buildmark). Panel and inverter manufacturer warranties (10–25 years) transfer to you as the property owner.

Solar Panels for New Build Homes

Last updated: 18 March 2026

Independently written

New build housing estate with solar panels on multiple homes — New builds increasingly come with solar panels — but check the system size and specification.

Do new build homes come with solar panels?

New build homes in England must meet Part L Building Regulations, which typically requires some renewable energy generation. Many developers install 1–2kW solar systems to meet the minimum requirement. This is often smaller than optimal — you may want to upgrade to 4–5kW before or shortly after moving in. Check the system specification, inverter type, and MCS certification before completing your purchase.

Building Regulations and Solar on New Builds

Since June 2022, new homes in England must produce 31% less carbon than previous standards under updated Part L Building Regulations. Solar panels are one of the most common ways developers achieve this.

What this means in practice: - Most new builds now include some solar capacity - Typical developer installation: 1–2.5kW (3–6 panels) — often the minimum to meet regulations - This is smaller than the optimal 4–5kW system for a typical family home - The panels are integrated into the house price — you do not pay separately

Future Homes Standard (2025+): - Expected to require 75–80% carbon reduction vs current standards - Will likely mandate larger solar systems on all new homes - May require heat pumps as standard heating

Source: UK Government Part L Building Regulations 2021; Future Homes Standard consultation.

New build detached home with solar panels meeting Part L regulations — Part L regulations require new homes to include renewable energy — solar is the most common choice.

Common Issues with Developer-Installed Solar

Watch out for these problems with new build solar:

Undersized system — developers install the minimum to meet regulations (1–2kW), not the optimum for your needs (4–5kW). A 1.5kW system saves £200–£300/year; a 4kW system saves £580–£820.
Budget panels — developers choose the cheapest panels available, not the most efficient. Check the brand, warranty terms, and efficiency rating.
String inverter on a partially shaded roof — new estates often have close-packed houses creating mutual shading. Micro-inverters perform better in these conditions.
No battery-ready inverter — if the developer installs a basic string inverter, adding a battery later requires replacing the inverter (additional £1,000–£1,500). Request a hybrid inverter.
Missing MCS certificate — the system must have MCS certification for SEG eligibility. Some developers delay or fail to provide this. Insist on it before completion.
No monitoring setup — developers often leave the inverter WiFi unconfigured. Ask the developer or installer to connect monitoring before handover.
Panels on a non-optimal roof face — developers may install panels wherever is easiest for construction rather than where they generate most electricity.

Checking new build solar installation documentation and MCS certificate — Insist on MCS certification and full documentation before completing your new build purchase.

What to Check Before Buying a New Build with Solar

System size (kWp) — is it 1.5kW minimum compliance or 4kW+ optimal?
Panel brand and model — are they from a reputable manufacturer with 25-year warranty?
Panel efficiency — 20%+ is good; under 18% is budget quality
Inverter type — string, micro, or hybrid? Hybrid is best for future battery addition
Inverter brand — GivEnergy, SolarEdge, Enphase are good; unknown brands are risky
MCS certification — will you receive the MCS certificate at completion?
Roof orientation — which direction do the panels face? South is ideal, east/west is acceptable
Warranty documentation — panel warranty, inverter warranty, installer workmanship warranty
Monitoring — will WiFi monitoring be set up before handover?
Can you upgrade? — can additional panels be added to the existing system later?

Upgrading New Build Solar: Adding More Panels

If your new build comes with a small system (1–2kW), you can usually add more panels:

Option 1: Expand the existing system - Add panels to the existing mounting rails and inverter - Cheapest option if the inverter can handle additional capacity - Cost: £200–£350 per additional panel (including installation) - May require DNO re-notification if the total exceeds 3.68kW

Option 2: Add a second system - Install a separate set of panels with their own inverter - More expensive but allows different inverter type (e.g., adding hybrid for battery) - Useful if the original system uses all available space on one slope - Cost: similar to a new installation minus scaffolding if still available

Best approach: Before moving in, ask the developer if they can install a larger system as an upgrade (often called a 'solar upgrade package'). This is cheaper than retrofitting later because scaffolding and electrical work are already planned.

Source: MCS system expansion guidance.

Expanded solar system — adding panels to a new build installation — Ask the developer about a solar upgrade package — easier and cheaper than retrofitting later.

New Build vs Retrofit: Cost Comparison

Solar on a new build is generally cheaper than retrofitting an existing home:

New build solar advantages: - No scaffolding cost (already in place during construction) - Roof structure designed with panels in mind - Electrical infrastructure planned from the start - In-roof panels possible at lower premium (no tile removal needed) - Often included in the mortgage (spread over 25 years at low interest)

Approximate costs: - New build 4kW system (included in build): £3,000–£5,000 (absorbed into house price) - Retrofit 4kW system (existing home): £5,500–£8,000 (paid separately)

If you are buying a new build, upgrading the solar system during construction is one of the best-value improvements you can make.

Source: NHBC new build renewable energy guidance.

Solar cost versus savings — new builds benefit from lower installation costs — New build solar is 20-40% cheaper than retrofit — making the ROI even stronger.

Find out how much you could save

Answer a few questions and receive personalised solar quotes — completely free.

Start My Quote

Free, no obligation. Takes 2 minutes.

Frequently Asked Questions

Ready to see what solar could save you?

Get free, no-obligation quotes from MCS-certified installers in your area.

Get Free Quotes