What percentage of homes in Cardiff are below EPC band C?

44.4% of rated homes in Cardiff are below EPC band C (as of 2026-Q2) — 51,496 of 115,947 rated dwellings. Source: The Home Index, from EPC Open Data under the Open Government Licence.

How many homes in Cardiff need upgrading to reach EPC band C?

51,496 rated dwellings in Cardiff sit below EPC band C and would need improvement to reach the band-C standard.

How does Cardiff rank for the EPC band C retrofit gap?

Cardiff ranks #248 for the widest retrofit gap among local authority areas in England and Wales.

Local authority diagnosis

Cardiff

Name: The Home Index — Cardiff
Creator: The Home Index
License: https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/

W06000015vintage 2026-Q2#248 by retrofit gap

In Cardiff, 51,496 rated homes sit below EPC band C. That puts the area at #248 for the widest gap among local authority areas in England & Wales.

Direction of travel

On current pace, reaches band C by 2045

Projection from the 15-year rated-stock trend; not a forecast.

Retrofit gap

44.4%

of 115,947 rated domestic dwellings are below band C.

EPC Open Data · Open Government Licence · free to cite with attribution.

Homes below band C

51,496

League rank

#248

1 = widest gap.

Cost to reach band C

£410.2m(modelled estimate of the cost to reach band C)

Position and trajectory

Is the gap closing?

The latest position for Cardiff, set against the recent direction of travel.

Fig.1Retrofit gap over time

Stock · year-end

Share of Cardiff's rated dwellings below band C at each year-end, ending at its headline 44.4%. Tracks every home by its latest certificate. EPC register.

Land Registry × EPC — matched-sale signals

What is at stake in the local market

We match HM Land Registry sales to EPC certificates: price per m², below-C matched-sale exposure, the observed C-or-above price/m² spread, and transaction-rate signals. Modelled estimates, shown with match coverage; not valuations. Methodology

Matched-sale exposure

£6.9bn

estimate for below-C stock; not a valuation.

Median sale price

£253k

typical matched sale here.

Matched sale £/m²

£3,087/m²

median, from matched sales.

Spread vs cost

1.05×

observed C+ price/m² spread ÷ modelled cost-to-C.

38.4% coverageMatched-sale estimate from recent HM Land Registry sales. Not a valuation. Methodology.

Matched sale £/m²

£3,087/m²

Matched-sale exposure

£6.9bnmatched-sale estimate of below-C rated stock value; not a valuation

C+ sale-price premium — size/type/location controlled

+5.1%

Homes rated C or better sell for ~+5.1% more per m², holding size, type and location constant (95% CI +5.1%–+5.1%).

Below-C transaction rate

0.86×

Local context

Fuel poverty & deprivation here

WIMD provides current local deprivation context. The latest Welsh fuel-poverty estimate is national only, so no local percentage is inferred for this authority.

Neighbourhoods in the most-deprived 10%

17.0%

share of LSOAs in the most-deprived national decile · Welsh Index of Multiple Deprivation 2025.

Private rented sector

The rented-stock cut

49.2% (based on 87.6% tenure coverage)

Make it specific

Area averages cannot tell you what one home needs.

Check a real address in Cardiff for its EPC, running costs, route to band C and available support. Landlords can then compare that home across a portfolio.

Check a home →Check a portfolio →

Prefer a general estimate? Model a home type in the cost calculator.

For local reporters: this is Cardiff's citable figure — copy the line below or embed the live widget, free to use with attribution.

Cite this figure / embed

Citation

The Home Index (2026-Q2): Cardiff has a retrofit gap of 44.4% — the share of rated homes below EPC band C. Source: EPC Open Data (Open Government Licence).

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<iframe src="https://thehomeindex.org/embed/lad/W06000015" width="320" height="200" style="border:0" title="The Home Index — Cardiff" loading="lazy"></iframe>