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Energy Bill Savings Calculator

Estimate annual savings from upgrading your home's energy efficiency, based on EST and Ofgem benchmarks.

Short answer

The biggest annual savings on a typical UK 3-bed semi: solar PV (£900–£1,100), cavity wall insulation (£285), loft insulation to 270mm (£250), smart thermostat (£75). Total potential: ~£1,700/year — though most homes won't capture all four. Payback ranges from 2 years (loft top-up) to 8–10 years (solar).
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Your home

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Calculation method, coverage and version

Inputs used
Current annual energy bill, Add loft insulation?, Add cavity wall insulation?, Install solar PV?, Install smart heating controls?.
Calculation approach
The calculator applies the rules and assumptions described in “How it works” to the values you enter. Rounding can cause small differences from an official or provider calculation.
Coverage
Home Grants & Energy. UK nations, tax treatment, local rules and provider criteria can differ; check the official sources shown below before acting.
Content version
No page-specific review date is currently published. Treat the result as indicative and verify current rules independently.
Not included unless explicitly requested: personal circumstances not entered, provider discretion, future rule changes, professional fees and case-specific exceptions. Read the full calculator methodology.

Primary sources and official verification

Use these official sources to verify current rules before acting. Coverage and dates can differ across England, Scotland, Wales and Northern Ireland.

See the sitewide source policy.

How it works

The calculator uses Energy Saving Trust 2024 benchmarks for a typical gas-heated 3-bed semi at the current Ofgem price cap. It sums the per-measure savings you select, then shows the percentage reduction against your stated bill. Higher bills generally mean larger absolute savings.

Worked example

£2,400 annual bill, no insulation, no solar → adding loft + cavity + smart controls saves ~£610/year (25% off) for a payback under 4 years. Add solar and battery and you double that.

Who should use this

  • •Homeowners planning a phased retrofit
  • •Renters checking which low-cost measures are landlord-approved
  • •Anyone shocked by their last winter bill

Common mistakes

  • ×Installing solar before insulating — wastes generation
  • ×Overspending on a smart thermostat without a wet heating system
  • ×Cavity wall insulation in unsuitable exposed homes (causes damp)
  • ×Believing 100% savings claims from cold-callers

Frequently asked questions

Should I insulate or get solar first?▾

Insulate first. Reducing demand makes any later renewable system cheaper and smaller.

Is a battery worth it?▾

Increasingly yes — pairing a 5kWh battery with solar typically adds £200–£400/year by exporting at peak times and using cheap overnight Octopus tariffs.

Will savings keep up with prices?▾

If energy prices rise, your savings rise too — that's the hidden upside of efficiency.

Related calculators

Solar PV Savings Calculator →Insulation Grant Checker →Heat Pump Cost Calculator →Energy Bill Estimator →