Loft insulation top-up in South Glamorgan

Where we work around South Glamorgan

Council areas covered: Cardiff and Vale of Glamorgan.

Postcodes starting CF are all inside our area.

Councils	Cardiff and Vale of Glamorgan
Postcode areas	CF
Towns listed	6

What is a loft insulation top-up?

Before we quote we measure the existing layer in several places and check its condition. If it is wet, dirty, matted or full of droppings, laying fresh wool on top just buries the problem, so we say so and price removal instead. More about a loft insulation top-up.

Gaps in the existing layer filled
Tank jacket and pipe lagging in the loft
Cross layer to a total of 270 to 300 mm

Why book with us in South Glamorgan

Fixed written price

The price on the quote is the price you pay. It only changes if you change the job, or if we find something hidden, such as rot, and you agree the change in writing first.

No pressure selling

You get everything in writing and decide in your own time.

Honest about grants

If you might qualify for funding, we tell you before we quote.

Clear contact details

Your quote says who to call with questions before, during and after the work.

How much does a loft insulation top-up cost in South Glamorgan?

£395 to £545Terraced house, average loft, topping up from about 100 mm. Free survey and a fixed written quote before any work.

Installing insulation in a home is zero-rated for VAT until 31 March 2027 and 5% after that, under HMRC's rules for energy-saving materials (notice 708/6). The Energy Saving Trust puts a typical professionally installed loft at about £750 from bare joists, or £600 to top up from 120 mm.

Work out a guide price for your loft

Building regulations in Wales

Wales has its own Approved Document L. Insulation alone is not normally notified, but conversions need building control. How the rules work across the UK.

Funding in Wales

Warm Homes Nest, run for the Welsh Government, offers free improvements to eligible low-income households.
ECO4, the energy supplier scheme, runs until 31 December 2026 for eligible households.
Check Nest's eligibility checker before agreeing to any funded offer.

Welsh Government: Warm Homes Nest

Questions about a loft insulation top-up in South Glamorgan

How do I book a survey in South Glamorgan?

Send the form or call us. We call back to agree a time and confirm it in writing.

Which council covers my address in South Glamorgan?

Councils in South Glamorgan include Cardiff and Vale of Glamorgan. Your council matters for building control questions and some funding schemes.

Can new insulation go on top of old insulation?

Yes, if the old layer is dry, clean and reasonably even. If it is damp, contaminated or badly compressed we recommend removing it first.

Is it worth topping up 100 mm of loft insulation?

Often, if the existing layer is in good condition and you also want a warmer house or a better EPC. On bill savings alone, a top-up from about 100 mm takes decades to pay back, so the case is strongest when it is done alongside other loft work.