Download this helpful guide to read about how DGCOS & ASSURE work together to cover and certify your home improvements.


County Windows Accreditation

Assure Windows and Doors

What does ‘Assure’ mean for customers?
…A greater level of protection.

High quality windows and doors can be a significant investment for homeowners.

This scheme offers customers the confidence they require by using Assure-certified installer.

When customers choose an Assure-certified company, homeowners will be assured that:

  • Their installation complies with Building Regulations.

  • Windows are the Energy Rated ones they ordered.

  • All Installers and Surveyors are fully qualified and regularly audited to ensure that they are up to date with the latest regulations and practices.

  • The installation is covered by an insurance-backed guarantee.
  • A sample selection of installations is independently audited to ensure the highest standards are being upheld.
  • Double Glazing Quality Assurance Scheme

    All perspective members are rigorously vetted before being allow to join our trusted network of installers. DGCOS have put in place a 12 point accreditation process in which every member must satisfy before being offered membership.


  • Undergo a five point credit and background history check on the proprietors/directors which includes multiple phoenix checks, credit scores, CCJ checks and similar trading name checks.

  • Provide DGCOS administrators with a minimum of 10 customer references (of installations carried out within last 12 months) who can be independently approached for quality assurance purposes.

  • Provide DGCOS administrators with a minimum of 3 supplier references who can be independently approached for quality assurance purposes.

  • Provide DGCOS administrators with a copy of their current Health and Safety Policy.

  • Carry minimum insurances of a) £5m Public Liability b) £10m Employers Liability.

  • Provide every customer with a Written Contract (to include Terms and Conditions).

  • Provide every customer with a Written Guarantee.

  • Provide every customer with Deposit Protection Insurance (where a deposit has been taken).

  • Provide every customer with an Insurance Backed Guarantee.

  • Comply with building control regulations on every installation.

  • Allow DGCOS Inspectors to inspect any installation deemed necessary.

  • Allow DGCOS to send every customer a Satisfaction Questionnaire.
  • Submit to the legal jurisdiction of DGCOS and the Ombudsman.
  • Credentials
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