Renovation calculator · Cardiff · 2026
Renovation cost calculator for Cardiff.
Cardiff renovation costs sit close to the BCIS UK national mean. Welsh labour day-rates run broadly aligned to the West Midlands. The dominant housing stock is Victorian and Edwardian redbrick terraces (Pontcanna, Canton, Roath, Cathays, Splott) plus interwar suburban semis (Heath, Llandaff, Whitchurch, Rhiwbina). Cardiff Council operates a tighter Welsh planning regime than the English GPDO, with the Town and Country Planning (General Permitted Development) Order 1995 (as amended in Wales) governing PD rights. The Welsh regime is broadly similar to the English one but with subtle differences on extension depths and conservation-area scope. Typical structural renovation: £160,000–£210,000.
Regional uplift vs national mean: −5% to +5% · BCIS Q1 2026 derived
Typical projects in Cardiff 2026
Per-m² and per-project mid-range bands for Cardiff, derived from BCIS Q1 2026 with the city’s specific uplift factor applied. Ex-VAT, including contingency and labour at local FMB day-rates.
| Project | Mid-range £ | Range in Cardiff |
|---|---|---|
| Kitchen renovation (full strip + replace) | £21,500 | £12,800 – £43,000 |
| Single-storey rear extension (20 m²) | £50,500 | £34,500 – £75,500 |
| Flood-zone risk assessment + works mitigation | £4,500 | £2,500 – £8,500 |
| Loft conversion with rear dormer | £52,500 | £38,000 – £72,500 |
| Full electrical rewire (3-bed) | £8,300 | £5,200 – £12,800 |
BCIS Q1 2026 + FMB 2026 + ONS COPI, restated for Cardiff. Ex-VAT, 10% contingency. Excludes professional fees.
Pontcanna, Canton and Cathays Conservation Areas in Cardiff impose tighter restrictions on external alteration than the city's outer suburbs. Listed Buildings cluster around Cathays Park, the Castle Quarter and parts of Canton. The Welsh-specific concern for renovators is the Welsh Government's flood-risk planning policy (TAN15) which applies to any extension or material alteration in defined flood zones — the Taff and Ely floodplains, plus Cardiff Bay's reclaimed land. A flood risk assessment is required for many flood-zone applications and can cost £1,500–£3,500. The other Welsh-specific issue is the 6% Land Transaction Tax (LTT) surcharge on second homes — relevant if you're renovating a property you don't occupy.
Run a full estimate for your Cardiff project
Five short steps, three spec tiers, itemised breakdown including the −5% to +5% uplift for Cardiff. Free, no sign-up.
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Long reads
Want the reasoning behind the Cardiff numbers?
The cost guide explains where the underlying BCIS + FMB ranges come from. The AI guide covers how we tested Claude against a chartered QS on a real Inner-London property — useful context for any UK renovation, including Cardiff.
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