Insulation costs in Swansea (2026)
A typical installation costs £375 to £1,200 in Swansea. Wales has some of the UK's lowest installed costs, around 5% below the UK average on MCS data, though rural mid-Wales jobs can carry travel surcharges.Here's what to expect by property type, and how to pay less.
Insulation costs in Swansea at a glance
| Type | From | To |
|---|---|---|
| Loft insulation (top-up) | £275 | £700 |
| Loft insulation (from scratch) | £450 | £1,200 |
| Cavity wall insulation | £375 | £1,200 |
| Solid wall, internal | £4,600 | £15,300 |
| Solid wall, external | £7,400 | £22,400 |
| Underfloor insulation (suspended) | £750 | £2,000 |
Indicative 2026 ranges adjusted for Wales, calibrated against MCS regional installation cost data and Ofgem grant-scheme averages. Always compare multiple quotes — prices vary by installer and property.
Costs by property type in Swansea
Pre-1920s terraces and period homes
Older solid-wall homes can't take cheap cavity fill; internal wall insulation runs £4,600 to £15,300 in Swansea, external systems more. ECO4 funding can cover much of this for eligible households.
Inter-war and post-war semis
Cavity-walled semis are the cheap win: £375 to £1,200 in Swansea, and often free through the Great British Insulation Scheme. Check whether the original cavity was ever filled.
Detached houses
More wall and roof area means bigger jobs, but loft insulation stays affordable at £450 to £1,200 in Swansea and pays back fastest of any upgrade.
What's different about Wales
- Wales has some of the UK's lowest installed costs, around 5% below the UK average on MCS data, though rural mid-Wales jobs can carry travel surcharges.
- Valleys terraces are often solid-walled, ruling out cheap cavity fill, while many rural homes are off the gas grid where heat pumps replace expensive oil or LPG.
- The £7,500 Boiler Upgrade Scheme applies in Wales, alongside the Welsh Government's Nest scheme for eligible households, ECO4, GBIS and the £350 OZEV charger grant.
Common questions
How much does insulation cost in Swansea?
A typical installation costs £375 to £1,200 in Swansea in 2026. Wales has some of the UK's lowest installed costs, around 5% below the UK average on MCS data, though rural mid-Wales jobs can carry travel surcharges. The table above shows ranges by system size and property type.
Why do prices in Wales differ from the UK average?
Wales has some of the UK's lowest installed costs, around 5% below the UK average on MCS data, though rural mid-Wales jobs can carry travel surcharges. Valleys terraces are often solid-walled, ruling out cheap cavity fill, while many rural homes are off the gas grid where heat pumps replace expensive oil or LPG.
What grants are available in Wales?
The £7,500 Boiler Upgrade Scheme applies in Wales, alongside the Welsh Government's Nest scheme for eligible households, ECO4, GBIS and the £350 OZEV charger grant.
How do I get an accurate price for my home?
Ranges only narrow once an installer sees your property. Compare quotes from several vetted local installers, free and with no obligation, and contact them free through Find an Eco Installer. No spam calls.
Get accurate Swansea quotes
The ranges narrow fast once installers see your property. Compare free quotes from vetted installers around Swansea, with replies typically within 24 hours.
Find installers across Wales
Compare vetted local installers town by town.
Also covering Aberystwyth and Bangor.
Insulation costs in other regions
- London
- the South East
- the East of England
- the South West
- the West Midlands
- the East Midlands
- Yorkshire
- the North West
- Scotland
Swansea prices follow Wales rates. See the full Wales guide.