EPC Rating Improvement Calculator

See which energy upgrades will improve your EPC rating the most, and how much they'll cost.

Enter your current EPC rating and tick what you already have installed. The calculator ranks the remaining upgrades by EPC impact and shows cost, annual savings, and grant eligibility for each.

What do you already have installed?

D

Current rating

D (55–68 SAP)

A

Projected rating

A (92–100 SAP)

Total annual saving

£2,110

Total investment

£27,350

Upgrades recommended

7

Upgrades ranked by EPC impact

1Air source heat pump
+1530 SAP ptsGrant

Install cost

£9,000 – £12,000

Annual saving

£300 – £650

Payback

~22.1 yrs

£7,500 BUS grant available (England/Wales)

2Cavity wall insulation
+1020 SAP ptsGrant

Install cost

£600 – £1,000

Annual saving

£250 – £400

Payback

~2.5 yrs

ECO4 / GBIS may fund this fully

3Loft insulation (270mm+)
+1015 SAP ptsGrant

Install cost

£400 – £700

Annual saving

£200 – £300

Payback

~2.2 yrs

ECO4 / GBIS may fund this fully

4Solar PV panels
+515 SAP pts

Install cost

£4,500 – £8,000

Annual saving

£400 – £650

Payback

~11.9 yrs

5Double / triple glazing
+510 SAP pts

Install cost

£4,000 – £9,000

Annual saving

£140 – £220

Payback

~36.1 yrs

6Condensing boiler upgrade
+38 SAP pts

Install cost

£2,000 – £3,000

Annual saving

£150 – £300

Payback

~11.1 yrs

7Smart thermostat
+25 SAP pts

Install cost

£150 – £350

Annual saving

£80 – £180

Payback

~1.9 yrs

* SAP point improvements are typical estimates based on the Standard Assessment Procedure. Actual improvements depend on your specific home and current specification. Get a formal EPC assessment to confirm your rating.

Frequently Asked Questions