Tel: 01443 858710 - (South Wales)   Tel: 01543 477350 - (Midlands)


Gas Safe Register is the official gas registration body for the UK, Isle of Man & Guernsey. By law all gas engineers must be on the Gas Safe Register. Gas Safe Register replaced CORGI as the gas registration body in Great Britain and Isle of Man on 1/4/2009 and Northern Ireland and Guernsey on 1/4/2010.

CHAS is the The Contractors Health and Safety Assessment Scheme. CHAS is established as the market leader for health and safety pre-qualification in the UK. It is available to suppliers (those who provide goods and services) and to organisations (buyers) looking for suitably competent suppliers.

We are proud to have achieved ISO 9001 status for our Management Systems through Alcumus ISOQAR. Our certificate number is 11952.

Constructionline is a UK government certification service which is the home of 000s of the best pre-qualified construction contractors & companies, as well as the Acclaim Accreditation.

The NIA represents the insulation industry in the UK; their members include installers and manufacturers who provide a wide range of insulation solutions. The NIA is fully committed to maintaining and raising standards within the insulation industry ensuring that ‘Peace of Mind’ comes at standard for customers. The NIA has a Code of Professional Practice that members agree to follow to ensure that the public receive the highest possible level of customer service.

Customer feedback

  • “Jefferies have proven themselves professional, with personable and proactive Site Management. They have been responsive to issues and change requirements and willing to adapt to tenant needs, which is very important to us as a client.”

    Caerphilly Council
  • “Jefferies Contractors Ltd has operated on various sites concurrently and it is with confidence that I can report that their sites are well managed, with a strong site management presence. The delivery teams on site have been considerate and courteous throughout, ensuring that our tenants are as comfortable as possible during the works process.”


Contact us today to discuss your project