Does insulation affect solar performance?

Not directly — but indirectly yes. Better insulation means less heating needed, so more of your solar electricity goes to other uses (or export) rather than heating. Net result: better solar ROI.

Can I get grants for both?

Yes — ECO4 covers insulation for eligible households (low income, EPC D-G). Solar gets 0% VAT. The two grants are independent — you can claim both.

What insulation should I do first?

Loft insulation — cheapest, fastest payback, DIY possible. Then cavity walls (if applicable). Then floor insulation. Then consider solid wall insulation (expensive but effective for older homes).

Is it worth insulating a new build?

New builds (post-2006) already have good insulation. Solar panels are the priority for new builds — the insulation is already done, so solar delivers maximum benefit from day one.

Solar and Insulation UK

By Home Solar Guide Team|Updated 18 March 2026|guide

Independently written | Evidence-based | Sources cited

Solar and insulation — Insulation + solar = maximum energy savings. Install insulation first, then solar.

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.

Ready to see how much you could save?

Get 3 free quotes from MCS-certified installers in your area.

Get Free Quotes

Should I insulate before installing solar?

Insulation and solar panels are the perfect energy-saving combination: INSULATION reduces how much energy you WASTE. SOLAR generates free energy. Together: 50-80% reduction in energy bills. Priority order: (1) LOFT INSULATION: £300-£500. Saves £150-£250/yr. Payback: 1-3 years. (2) CAVITY WALL INSULATION: £500-£1,000. Saves £100-£200/yr. Payback: 3-5 years. (3) SOLAR PANELS: £5,500-£9,000. Saves £580-£1,100/yr. Payback: 8-12 years. (4) SOLAR BATTERY: £4,000-£6,000. Extra £200-£400/yr savings. (5) HEAT PUMP: £3,500 after BUS grant. Saves £200-£400/yr on heating. Total potential savings: £1,200-£2,000/yr. Insulation first because it's cheap and maximises solar benefit — a well-insulated home needs less energy, so more solar can be exported or stored.

Frequently Asked Questions

Related: Home Heating Systems

Solar panels are most powerful when combined with an efficient heating system. Heat pumps use solar-generated electricity to heat your home at 300-400% efficiency — making them the ideal partner for solar.

air source heat pump guide

Learn more about how air source heat pumps work alongside solar panels.

heat pump grants and the BUS scheme

The Boiler Upgrade Scheme offers £7,500 towards heat pump installation.

heat pump running costs in the UK

Heat pumps use electricity at 300-400% efficiency, making them ideal partners for solar.

From our sister site Home Heat Pump Guide