EPC improvement case studies
What cheapest-points-first sequencing actually does: a documented Victorian terrace lifted from E to C without touching the walls, a cavity semi over the line for under £1,000, and an unlettable shop made lettable again. One is a published, attributed case; the others are illustrative and clearly labelled.
Documented: Victorian solid-wall terrace, EPC E (48) to C (77) for ~£8,550, no wall insulation
- EPC band
- E → C
- Points gained
- +21
- Total cost
- £8,550
The scenario
Published real-property case (The Independent Landlord, Suzanne Smith, cite and link as the source). A late-Victorian solid-wall mid-terrace rental with a cellar started at EPC E with a score of 48-21 points short of band C. The received wisdom said solid-wall insulation at £8,000-£15,000; the recommendation report and sequencing said otherwise.
The measures
RdSAP domestic assessment; measures: loft top-up 100mm to 300mm (£800), suspended-floor insulation from the cellar (~£150 materials within a £2,300 cellar-ceiling job), front-elevation double glazing (£5,400, +2 points per the recommendation report); boiler already modern condensing, no spend
The outcome
Re-assessed at C (77), a 29-point gain from E (48) for around £8,550 total, achieved WITHOUT wall insulation and WITHOUT a new boiler. The two lessons the whole niche turns on: the loft top-up delivered points at roughly £95 each while the glazing cost about £2,700 per point, and the certificate's own recommendation report, sequenced cheapest-first, beat the £15,000 scare quote. New certificate lodged, valid ten years.
Mid-D cavity semi to C for under £1,000 (illustrative)
- Points gained
- +2
- Total cost
- £1,000,
The scenario
Illustrative scenario, clearly labelled. A 1950s cavity-wall three-bed semi rated D (63), six points short of C, with a working but poorly controlled gas system, halogen spots, partial loft insulation and a bare hot-water cylinder. The owner was quoted £4,800 for glazing 'to reach C'.
The measures
RdSAP domestic assessment; quick-win package: LED throughout (~£60), 80mm cylinder jacket (~£25), programmer + room stat + TRVs (~£420), loft top-up to 300mm (~£450)
The outcome
Re-assessed comfortably into band C: the controls, lighting, cylinder jacket and loft top-up together delivered the needed points for under £1,000, the glazing quote would have bought roughly 2 points for five times the money. Evidence pack (invoices, product details, depth photos) handed to the assessor per RdSAP 10, so every measure scored. Illustrative of the published cost-per-point ranges, not a guaranteed outcome.
F-rated shop unit back over the MEES line with lighting and heating (illustrative)
The scenario
Illustrative scenario, clearly labelled. A ~120 sqm high-street retail unit assessed EPC F after a tenant left, unlawful to re-let without a registered exemption. Open shopfront, ageing electric heating, fluorescent and halogen lighting throughout. The owner needed it lettable fast and wanted the cheapest compliant route, not a refurbishment.
The measures
SBEM Level 3 (non-domestic) assessment; measures: full LED retrofit with occupancy/daylight controls, replacement efficient electric heating with controls
The outcome
Re-assessed at a solid E, lettable again, with lighting and heating doing all the work, exactly the levers the EPC's recommendation report ranked first. The unit re-marketed within days, and the owner received a costed forward plan toward the higher bands given the proposed EPC B by 2031 standard applies only to buildings over 1,000 sqm (this one is not in scope, but tenants increasingly discount weak-EPC space anyway).