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Isleworth · Greater London

Existing insulation and guarantee check in Isleworth

Isleworth homeowners, buyers, landlords and agents can book an insulation and guarantee check with the price agreed first. An existing insulation check tells you whether a cavity is filled, what with, whether it looks dry and intact, and how to trace any guarantee.

Book an insulation check in Isleworth

Covering Isleworth and the TW7 district. Tell us about the property. We confirm the price before you book.

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We use your details only to answer this enquiry and arrange your visit, sharing them only with the registered installer we appoint for your job and the providers named in our privacy notice. No marketing lists, no cold calls.

Existing insulation and guarantee check for Isleworth properties

Our Greater London coverage takes in Isleworth (TW7) and nearby Hounslow, Heston and Richmond. It is about 9 miles west of London.

Every inspection point in Isleworth is photographed and logged, so you have a record to show a buyer, lender or contractor. Where an Isleworth wall shows cold patches or damp, the survey targets those areas first rather than sampling at random.

Local weather affects which walls can be filled. Much of Greater London sits in the more sheltered driving-rain zones of the UK, which widens the choice of fill. Exposed elevations, coastal sites and high ground still get checked wall by wall.

In terms of approvals, if cavity wall insulation follows in Isleworth, filling a cavity is notifiable building work and needs a building notice or competent-person self-certification.

Rules in England

Filling a cavity is notifiable building work and needs a building notice or competent-person self-certification if insulation work follows.

Sources: Planning Portal: cavity wall insulation and building regulations; CIGA: CWISC competent person scheme.

How to tell if a house already has cavity insulation

Look for a regular pattern of small patched holes in the mortar joints, often about a metre apart. Check the EPC, which may say 'filled cavity'. Ask the seller for a guarantee. The reliable answer is a borescope check, because patched holes can be from a fill that was later removed and EPCs are sometimes wrong.

What is included in Isleworth

  • Visual check of walls and patched holes
  • Guidance on tracing a guarantee
  • Borescope checks
  • Short written report

Guide prices for Isleworth

Existing insulation and guarantee check guide prices
Existing insulation and guarantee check guide pricesGuide price
Existing insulation and guarantee check£145–£245

This work is not insulation, so it is normally standard-rated for VAT. Guide prices include VAT where it applies. Guide ranges only: the fixed price is confirmed in writing before any work starts, and anything that could not be seen at survey is agreed with you first.

What happens next for an Isleworth property:

  1. Tell us what is happening

    Postcode, property type and what you have noticed.

  2. Price agreed first

    We confirm the price before anyone visits.

  3. Visit and checks

    Photos and readings at the areas that matter.

  4. Findings in writing

    What we found and the options, each priced separately.

Last reviewed 19 October 2026.

Existing insulation and guarantee check in Isleworth: questions

Do you cover Isleworth?

Yes. Isleworth and the TW7 postcode district are within our Greater London coverage, along with nearby Hounslow and Heston.

How soon can you visit in Isleworth?

We arrange dates when you get in touch. Availability varies through the year, so we give you real dates rather than a promise on the website.

Do you work on rented homes in Isleworth?

Yes. Landlords and agents in Isleworth can book batch visits, and work is arranged around tenants.

Is there VAT on an insulation and guarantee check in Isleworth?

Existing insulation and guarantee check is not insulation, so it is normally charged at the standard rate of VAT. The VAT treatment is confirmed on your quote.

Nearby towns

Book an insulation check in Isleworth

Priced before you book. Findings in writing. No cold calls.