ECO3 deemed scores


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This publication contains the ECO3 Deemed Scores Matrix, which can be used for measures delivered from 1 October 2018. 

The deemed scores presented in this document are ‘lifetime scores’, and relate to the average treatable area for the measure type. Additional versions of scores are included which incorporate any applicable uplifts. In some cases, the percentage of the measure installed and percentage of property treated must also be determined to ensure the correct score is notified.

Full guidance on the use of deemed scores is given in Chapter 6 of the ECO3 Guidance: Delivery document.

This page also includes any deemed scores which have been applied for by suppliers and approved by Ofgem. Once published on this page, any supplier can claim the scores for the appropriate measures, assuming all the relevant criteria are met.

Further information on the development of the deemed scores is published on our ECO3 deemed scores consultation decision page.

If you have a query about the deemed scores or their use, you can contact us at

ECO3 Deemed Scores Matrix - version information

Version 1.7 was published on 04 June 2021. The changes between version 1.7 and 1.6 are:

  • New deemed scores for Time and Temperature Zone Control (TTZC) measure type. TTZC is a type of heating control and the definition can be found on the Alternative Methodology page.

Earlier Versions

Version 1.6 was published on 19 April 2021. The changes between version 1.6 and 1.5 are:

  • Additional internal wall insulation (IW)) scores with a finishing U-value of 0.6 W/m2K for starting U-values of 1.7 and 1.0.

  • New deemed scores for 'fuel cell mCHP' (micro-CHP), as a post main heat source for boiler measures. ‘Fuel cell mCHP’ is a renewable heating measure and the same rules apply to ‘fuel cell mCHP’ as all other renewable heating measures installed under ECO3.
  • Addition of broken boiler and electric storage heater (ESH) measure scores with no uplift: 
    • 'B_broken' scores now have three variants – ‘N/A’ (no uplift); ‘broken_CH_secondary’; ‘broken_CH_cap_renew’
    • 'ESH_broken' scores now have two variants - ‘N/A’ (no uplift); ‘broken_ESH’

The ability to remove the uplift only applies to measures installed under the broken heating system cap, where the broken heating system does not meet the definition of a boiler (eg a warm air system) or where the heating system has been removed from the property.  Systems which do not meet the definition of a boiler, or where a heating system has been removed, cannot be claimed as a secondary heating measure.

Version 1.5 was published on 11 February 2020. The changes between version 1.5 and 1.4 are:

  • Addition of Bottled LPG Boiler as a heat source for all property archetypes.
  • Removal of 1 year warranty variants of boiler and ESH repair scores.
  • Removal “broken_CH_secondary” uplift variants for ASHP, GSHP, and Biomass scores.

Version 1.4 was published on 18 December 2019. These are deemed scores which will apply to all measures installed on or after 1 January 2020. Version 1.3 of the scores should continue to be used for measures installed prior to 1 January 2020. Version 1.4 contains the changes set out in the ECO3 Improving Consumer Protection consultation decision.

Changes between version 1.4 and 1.3 are:

  • Lifetime of FTCH measures has been increased to 20 years, and scores adjusted accordingly
  • Added variants of broken boiler replacement scores with the new 200% “broken_CH_secondary” uplift, and updated the name of the existing 400% uplift to “broken_CH_cap_renew”
  • Added new measure types weather/load compensation and solid floor insulation
  • Adjusted scores for installing Gas and LPG boiler to remove saving related to weather/load compensation
  • Renamed solid wall insulation measure category “External/internal wall insulation”
  • Removed score variants which combined the pre main heat source “Gas room heaters” with the non mains gas insulation uplift

Version 1.3 was published on 7 June 2019. The only change was the addition of scores relating to smart thermostats. Information on the use of these scores can be found in Chapter 6 of the ECO3 Guidance: Delivery document.

Version 1.2.1 and was published on 8 March 2019. Changes between v1.1 and v1.2 were:

  • The addition of a new measure type, CWI_partial_fill
  • The addition of new variants of non-insulation measure types incorporating the uplift “LA_F&G_nonPRS”
  • The addition of new variants of insulation measure types combining the heat source “Gas boiler*” and the uplift “nonmainsgas_insulation”

CWI measures installed to cavities with partial fill insulation where the measure is completed and handed over from 1 April 2019 onwards, must be notified using the CWI_partial_fill measure type. CWI measures installed to empty cavities should continue to be notified using the standard CWI measure types.

Version 1.2.1 was published on 8 March 2019 with the same changes as above, but was replaced, as two measure names (RIRI_res_in and RIRI_res_unin) contained errors.

Version 1.1 was published on 30 November 2018. Changes from the previous version were the removal of scores for the measure type “B_broken” relating to non-boiler heat sources. These heat sources should be replaced as first time heating measures.

Version 1.0 was published on 23 July 2018 alongside the ECO3 deemed scores consultation decision.