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G.A.S General Building Services Ltd

10/10

London

£1,000 guarantee T&Cs apply

Checkatrade member since February 2026

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Skills

  • Cavity Wall Insulation
  • Cavity Wall Insulation Removal
  • External Solid Wall Insulation
  • Flat Roof Insulation
  • Internal Solid Wall Insulation
  • Loft Insulation
  • Roof Joist Insulation
  • Roof Rafter Insulation

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Customer Reviews

Write a review

10 /10

Based on 7 reviews over the past 12 months

Quality of work

10

Reliability

10

Communication

10

Reviews (7)

  • 10

    Loft Insulation

    Posted 2 days ago

    consultation full house insulation + sound insulation

    RetrofitIQ did a great blower door test, thermal camera survey, air leakage investigation, smoke testing, etc consult for our house and provided a write up with pictures and weighted options to improve the house. It took around 4 hours and helped us find a lot of root causes of issues around the house.
    Verified reviewer
    Job location: SM1
    Zi-Tong D
  • 10

    External Solid Wall Insulation

    Posted 6 days ago

    Quality survey and service.

    George carried out a comprehensive building performance investigation at our property.The inspection included blower door testing, professional FLIR thermal imaging,smoke tracing,air leakage testing and a detailed assessment of the building fabric.He was extremely thorough,methodical and took the time to explain every issue and the reasons behind it.His approach was based on finding the root cause rather than offering quick fixes,and his knowledge and professionalism really stood out.I would not hesitate to recommend Retrofit IQ to anyone looking for a genuine building performance specialist.
    Verified reviewer
    Job location: NW4
  • 10

    Insulation

    Posted 13 June

    Excellent service from start to finish.

    Highly recommended. George was very friendly, professional, and knowledgeable. He carried out a blower door test, smoke testing, and thermal imaging survey and provided a detailed report explaining the causes of our heat loss issues. Everything was explained clearly, and the recommendations were practical and easy to understand. Excellent service from start to finish. ⭐⭐⭐⭐⭐
    Verified reviewer
    Job location: LU4
  • 10

    Sound Proofing

    Posted 07 June

    Excellent Service. Highly recommended.

    The work was done to perfection. We were always kept informed of what was happening and given advice of the best cost effective option. Anyone who choses this company will not be disappointed. They are extremely professional and good value for money. We will be using them again to do some more work. Thank you GAS.
    Verified reviewer
    Job location: N17
  • 10

    Suspended Floor Insulation

    Posted 05 April

    Underfloor insulation

    George was brilliant. We required the existing floor to be lifted and insulation installed. Throughout the process George was tidy, considerate and offered advice on how to achieve the best outcome. The team documented the process throughly with photos for my records. I would definitely use GAS again for similar works or general construction in our home.
    Verified reviewer
    Job location: E17
    Luke L
  • 10

    Insulation

    Posted 13 March

    Friendly and professional

    George was friendly, arrived on time and was very helpful during the assessment. He answered all of my questions and showed a passion for what he does. The report provided was very thorough and George was able to provide full costings for all proposed improvements to my flat. I highly recommend him!
    Verified reviewer
    Job location: IG8

Photos

+122

Company Info

Owner

Mr George Razvan Sora

Ltd Company

Member since 2026

VAT Registered

No

Domestic WorkCommercial WorkFree EstimatesCards Accepted

G.A.S General Building Services Ltd specialises in diagnosing and solving building performance problems such as heat loss, condensation, damp, mould, draughts, and sound transmission issues in residential properties.


Using professional diagnostic tools, including thermal imaging inspection, blower door air leakage testing, humidity assessment, and building performance analysis, we identify insulation defects, hidden air leakage paths, cold bridges, and acoustic weak points within the building envelope.


Our work follows building performance and Passive House design principles to ensure effective and long-term solutions. Where improvement works are required, installations such as insulation upgrades, acoustic floor systems, or airtightness improvements can be verified with before-and-after testing.


With over 15 years’ experience working with high-performance insulation, acoustic upgrades, and building envelope systems, our goal is to improve comfort, reduce heat loss, minimise unwanted noise transfer, and resolve the root cause of building performance problems.

This trade passed up to 12 Checkatrade vetting checks

Member since February 2026

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