greenhomesums
EPC C → B upgrade for EPC C → B (semi)
A C → B upgrade means you've already done the cheap wins. Now it's premium-cost measures — usually solar PV, a heat pump, or both.
Upgrade measure stack
Cheapest-first ordering — calculator stops adding measures once the gap to B closes.
| Measure | Cost | SAP uplift |
|---|---|---|
| Full LED lighting retrofit | £250 | +1.0 |
| Thermostatic radiator valves + controls | £400 | +1.0 |
| Air-source heat pump (BUS-eligible) | £11000 | +10.0 |
| Total | £11650 | to band B |
What's specific about this archetype
Homes at C have used the cheap insulation levers. B requires adding generation or removing fossil fuels: a 4 kWp solar array, or a heat pump to switch off gas. Payback is measured in 8–12 years on running-cost savings alone — but the resale and green-mortgage benefits typically add another 2–3% to the financial case.
Model your exact property
The figures above use a reference archetype. Your real floor area, mortgage balance, current energy bill and exact current band will shift the numbers. Use the full EPC upgrade calculator for a customised version, the insulation savings calculator to choose between competing fabric measures, and BUS grant eligibility if a heat pump is on the shortlist.
Other premium upgrades
| Archetype | Start → Target | Net cost | Annual saving |
|---|---|---|---|
| EPC C → B (semi) (this page) | EPC C → B | £4150 | £90/yr |
| EPC B → A | EPC B → A | £4150 | £96/yr |