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EPC E → C upgrade for Solid-wall terrace
Solid brick walls are the UK's single biggest EPC headache — they carry 35–40% of a typical home's heat loss and can't be fixed with the cavity-fill wand.
Upgrade measure stack
Cheapest-first ordering — calculator stops adding measures once the gap to C closes.
| Measure | Cost | SAP uplift |
|---|---|---|
| Full LED lighting retrofit | £250 | +1.0 |
| Thermostatic radiator valves + controls | £400 | +1.0 |
| Upgrade to modern double glazing | £6500 | +4.0 |
| Air-source heat pump (BUS-eligible) | £11000 | +10.0 |
| Solid wall insulation (internal or external) | £12000 | +12.0 |
| Total | £30150 | to band D |
What's specific about this archetype
Solid-wall insulation is the most expensive single measure in the calculator (£12,000+ for a decent terrace), and it's disruptive — internal wall insulation eats 80–100 mm off every external-wall room. External wall insulation is often blocked by conservation-area or planning rules on pre-1919 stock. Expect the solid-wall upgrade to be the tipping point in any pre-war home's journey to C.
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 wall-type archetypes
| Archetype | Start → Target | Net cost | Annual saving |
|---|---|---|---|
| Solid-wall terrace (this page) | EPC E → C | £22650 | £322/yr |
| Cavity-uninsulated semi | EPC D → C | £5350 | £171/yr |
| Timber-frame home | EPC C → B | £4150 | £90/yr |