Timber Window Accreditation (TWA)

The TWA (Timber Window Accreditation) Scheme provides one of the most rigorous and best supported of the UK certification schemes for wood windows. Set up in 1996 by a group of window manufacturing members of the BWF, it is the leading and longest established window accreditation scheme of its kind in the UK. All windows accredited under the Scheme are independently tested and audited to ensure they comply with the Scheme’s standards, and are covered by a series of warranties. The Scheme is managed by the BWF and includes manufacturers, as well as approved suppliers and installers, who play an important part in maintaining and advancing these standards. It is one of the certification schemes behind the Wood Window Alliance, which is responsible for marketing high quality independently audited wood windows.

The TWA Scheme aims to:

  • Ensure timber windows and entrance doorsets provide excellent quality, performance and durability
  • Provide the most rigorous and comprehensive third party testing of windows and doorsets and their manufacture
  • Promote the advantages of fully factory finished and factory double glazed timber windows and factory assembled doorsets
  • Encourage proper site practices when installing timber windows and doorsets.

The Kitemark

In addition to meeting the Scheme’s technical criteria, for their factory glazed timber windows manufacturers have to gain BSI Kitemark certification, requiring:

  • Independent and third party auditing of their products
  • Compliance with the TWA Scheme quality control requirements
  • Stringent operational and weather tightness tests for each window style
  • An annual audit test of a random window sample
  • Two rigorous factory inspections per year to ensure compliance with the technical criteria.

The TWA Scheme label Each label shows the TWA Scheme manufacturer’s logo, name and telephone number, a unique product reference number for traceability and a promise that the window is made from certified, sustainable and legal timber. If the window is fully factory finished it will come with the Kitemark logo, to show compliance with the BSI scheme and all the relevant service life warranties. If the window is supplied unglazed, it will not show the Kitemark logo, but the service life warranties will still apply (such as preservative treatment, or ironmongery etc). If the manufacturer is a member of the Wood Window Alliance, the label will have this logo too.

** Look out for new savings on BSI Kitemark certification fees from April 2014. As a BWF member, you can make significant savings by including BS 644 / PAS 24 Windows (Security) and BS 644 / PAS 24 Doors (Weather & Security) within the TWA scheme. You could save up to £3,500 per annum. Find out more here: www.bwf.org.uk/news/latest-news/new-savings-on-your-bsi-kitemark-certification-fees **