Typical planning ranges in Cardiff
What the Wales factor means
Our broad 0.91× regional model sits 9% below the national planning baseline. It is a UK Home Costs planning assumption rather than an externally measured city-wide price index. For projects with a large nationally priced equipment or materials component — such as solar, windows, EV chargers, insulation, underfloor heating and consumer units — the table uses only the documented share of that broad regional difference used by the corresponding calculator.
Planning considerations in Cardiff
- Use Wales-specific planning, building-control and energy-scheme information where the rules differ from England.
- Terraced or constrained urban properties can add access, waste and scaffold costs that are not captured by the regional factor.
- Drainage, roof and external-work scopes should be based on the property condition rather than a generic city assumption.
How to use these figures
For grants and energy schemes, verify the current Wales-specific eligibility rules before relying on any support assumption.
Start with the table to understand project scale, then use a calculator to add floor area, condition, finish level and other project-specific inputs. A postcode-aware calculator can infer the same broad region while still allowing a manual override.
Compare this region with all locations
Detailed project cost guides in Cardiff
These pages apply the same transparent regional model — or the calculator's documented moderated regional treatment where appropriate — to detailed project tables rather than publishing a single city-wide headline figure.
Extension cost
Modelled Cardiff extension cost using the current £1,800–£3,000 per m² national benchmark before VAT and the UK Home Costs Wales regional planning model.
£1,800–£3,000 per m² national benchmark before VATOpen Cardiff guide →2026 regional guideLoft conversion cost
Modelled Cardiff loft conversion cost using the current £22,500–£80,000 across common 2026 conversion types and the UK Home Costs Wales regional planning model.
£22,500–£80,000 across common 2026 conversion typesOpen Cardiff guide →2026 regional guideRoof replacement cost
Modelled Cardiff roof replacement cost using the current £4,000–£19,000 for most roof replacements; £8,000 UK average and the UK Home Costs Wales regional planning model.
£4,000–£19,000 for most roof replacements; £8,000 UK averageOpen Cardiff guide →2026 regional guideHouse rewire cost
Modelled Cardiff house rewire cost using the current £3,000–£12,500 across common flats and houses and the UK Home Costs Wales regional planning model.
£3,000–£12,500 across common flats and housesOpen Cardiff guide →2026 regional guideNew boiler cost
Modelled Cardiff new boiler cost using the current £2,500–£4,000 like-for-like combi; £3,000–£15,000 broader installed projects and the UK Home Costs Wales regional planning model.
£2,500–£4,000 like-for-like combi; £3,000–£15,000 broader installed projectsOpen Cardiff guide →2026 regional guideSolar panel cost
Modelled Cardiff solar panel cost using the current £6,000–£10,000 for 3–6 kW solar-only systems; about £8,000 for 4 kW and the UK Home Costs Wales regional planning model.
£6,000–£10,000 for 3–6 kW solar-only systems; about £8,000 for 4 kWOpen Cardiff guide →2026 regional guideKitchen renovation cost
Modelled Cardiff kitchen renovation cost using the current £5,250–£28,400 current fitted-kitchen range; £10,550 UK average and the UK Home Costs Wales regional planning model.
£5,250–£28,400 current fitted-kitchen range; £10,550 UK averageOpen Cardiff guide →2026 regional guideBathroom renovation cost
Modelled Cardiff bathroom renovation cost using the current £5,500–£8,000 typical new bathroom; £7,000 UK average; £14,000+ high-end and the UK Home Costs Wales regional planning model.
£5,500–£8,000 typical new bathroom; £7,000 UK average; £14,000+ high-endOpen Cardiff guide →2026 regional guideWindow replacement cost
Modelled Cardiff window replacement cost using the current £500–£5,000+ per double-glazed window by type; £8,000–£15,000 for a typical 3-bed house and the UK Home Costs Wales regional planning model.
£500–£5,000+ per double-glazed window by type; £8,000–£15,000 for a typical 3-bed houseOpen Cardiff guide →2026 regional guideHome insulation cost
Modelled Cardiff home insulation cost using the current £654–£1,206 for common loft-quilt examples; £950–£4,600 cavity-wall examples by property type and the UK Home Costs Wales regional planning model.
£654–£1,206 for common loft-quilt examples; £950–£4,600 cavity-wall examples by property typeOpen Cardiff guide →2026 regional guideEV charger cost
Modelled Cardiff ev charger cost using the current about £1,000 typical home installation; eligible 2026 OZEV grants cover 75% up to £500 per socket and the UK Home Costs Wales regional planning model.
about £1,000 typical home installation; eligible 2026 OZEV grants cover 75% up to £500 per socketOpen Cardiff guide →2026 regional guideExternal wall insulation cost
Modelled Cardiff external wall insulation cost using the current £150–£200 per m² installed; £6,000–£30,000+ across common property examples and the UK Home Costs Wales regional planning model.
£150–£200 per m² installed; £6,000–£30,000+ across common property examplesOpen Cardiff guide →2026 regional guideUnderfloor heating cost
Modelled Cardiff underfloor heating cost using the current £50–£110 per m² across electric and wet new-build or renovation systems; £3,000–£13,000 for many full-property installs and the UK Home Costs Wales regional planning model.
£50–£110 per m² across electric and wet new-build or renovation systems; £3,000–£13,000 for many full-property installsOpen Cardiff guide →2026 regional guideConsumer unit cost
Modelled Cardiff consumer unit cost using the current about £485 for a typical installed 10-way RCBO unit; roughly £350–£800 by circuits and property size and the UK Home Costs Wales regional planning model.
about £485 for a typical installed 10-way RCBO unit; roughly £350–£800 by circuits and property sizeOpen Cardiff guide →Popular calculators
House renovation
Refine the Cardiff planning range with project-specific inputs.
Open calculator →Live calculatorHouse extension
Refine the Cardiff planning range with project-specific inputs.
Open calculator →Live calculatorLoft conversion
Refine the Cardiff planning range with project-specific inputs.
Open calculator →Live calculatorGarage conversion
Refine the Cardiff planning range with project-specific inputs.
Open calculator →Live calculatorKitchen renovation
Refine the Cardiff planning range with project-specific inputs.
Open calculator →Live calculatorBathroom renovation
Refine the Cardiff planning range with project-specific inputs.
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