Insulation in Llanelli
£458 to £7,139 installed, and 63% of homes in the council area rated EPC D to G.
What insulation costs in Llanelli
Loft only
£458–£1,093
Saves up to £233 a year. Pays back in about 3 years.
Loft + cavity walls (most common)
£1,802–£4,298
Saves up to £478 a year. Pays back in about 6 years.
Full package
£2,994–£7,139
Saves up to £546 a year. Pays back in about 8 years.
Source: Home Energy Quotes Cost Index, costs modelled September 2026, savings at the October to December 2026 price cap. Prices are estimates and include installation and VAT. Actual costs may vary.
Llanelli in numbers
Published statistics for the Carmarthenshire council area, not our estimates.
63% of homes with an EPC in the Carmarthenshire council area are rated D to G, and the median energy score is 64, which is band D.
| Carmarthenshire council area | Figure | Source |
|---|---|---|
| Homes with an EPC rated D to G | 63% | ONS, EPCs lodged to March 2025 |
| Median EPC energy score | 64 (band D) | ONS, EPCs lodged to March 2025 |
| Households on mains gas heating only | 54.3% | Census 2021, ONS |
| Electricity network operator | National Grid Electricity Distribution (South Wales) | NESO licence area boundaries |
These are published official statistics for the Carmarthenshire council area, which covers Llanelli, not Home Energy Quotes estimates. Sources checked 6 October 2026.
Is Llanelli a good place for insulation?
The area’s housing stock includes a range of properties suited to insulation installations throughout Llanelli. Combined with Wales’s energy prices, insulation installations here may offer good value (individual results will vary).
Llanelli has a population of 42,155, and the area falls within the Wales region. We recommend getting at least 3 quotes to compare prices.
Find Installers in Llanelli
We recommend getting at least 3 quotes from qualified installers before making a decision. Check reviews, ask for local references, and make sure warranties are clearly stated in writing.
What to check before hiring an installer in Llanelli
- Qualifications — check the installer holds relevant qualifications and certifications for insulation before signing any contract
- Local references — ask for completed jobs in Llanelli or Carmarthenshire
- Reviews — check online reviews before committing
- Warranty — product and workmanship warranties should be clearly stated in writing
- 3 quotes minimum — we recommend comparing at least three quotes to ensure you get a fair price
Questions about insulation in Llanelli
How much does insulation cost in Llanelli?
How energy efficient are homes in Llanelli?
Is there a grant for insulation in Llanelli?
How long is the payback period in Llanelli?
Do I need planning permission in Llanelli?
How do I find a good installer in Llanelli?
Get quotes for your home in Llanelli
Up to three approved installers who cover Llanelli may contact you. Free, no obligation.
Llanelli on the map
Insulation in nearby towns
Last reviewed: . Costs are modelled estimates from the Home Energy Quotes Cost Index — see how we calculate them. Grant rates are checked against GOV.UK.