GBIS Calculator – Eligibility Checker

GBIS Calculator

Check your property eligibility and estimate your Partial Project Score.

1

Quick property check

2

Measure and scoring inputs

How this GBIS Calculator helps

Not sure whether your home could qualify for insulation support or what your GBIS score might mean? This calculator helps you make a quick, practical first check before you speak to a supplier or installer.

We know that navigating government schemes can be overwhelming. By entering your property details—such as your EPC rating, Council Tax band, and the type of insulation you need—we evaluate your eligibility signals. The tool then cross-references your inputs against the official Ofgem GBIS scores matrix to provide an estimated Partial Project Score (PPS) and personalised next steps.

How the GBIS Process Works

1. Estimate

Use this calculator to check basic eligibility.

2. Assessment

A qualified Retrofit Assessor visits your home.

3. Supplier

Energy supplier reviews the assessment & costs.

4. Install

A TrustMark installer completes the work.

Eligibility Routes at a Glance

Route EPC Requirement Council Tax Band Household Criteria
General Group (England) D, E, F, or G A, B, C, or D No specific income limit
General Group (Wales & Scotland) D, E, F, or G A, B, C, D, or E No specific income limit
Low-Income Group D, E, F, or G Any Band Qualifying benefits or LA Flex referral

What the Great British Insulation Scheme checks

Before any insulation measure is approved, the scheme mandates checks across a few critical areas:

  • EPC rating: To ensure the property actually needs energy efficiency improvements, typically bands D to G.
  • Council Tax band: Used to filter properties into the general eligibility group.
  • Household circumstances: Determining whether you meet the criteria for the low-income group, receive qualifying benefits, or can be supported via Local Authority Flex.
  • Property suitability: A certified retrofit assessment must confirm that the insulation measure is technically suitable for your building.

Ultimately, an obligated energy supplier will make the final decision based on their funding caps and current operational capacity.

What your GBIS score means

Your estimated GBIS score gives you an idea of the energy savings your projected measure might generate. However, it is vital to understand that a high Partial Project Score (PPS) is not the same as guaranteed cash in your pocket.

The funding estimate we provide depends entirely on the £/ABS rate inputted, which fluctuates between suppliers and installers. Some measures may be fully funded, while others might require a customer contribution to cover the total installation cost. An official retrofit assessor will confirm the final viable score.

Frequently asked questions