The TWA Scheme is the leading and longest established window accreditation scheme of its kind in the UK. The TWA (Timber Window Accreditation) Scheme was set up in 1996 by a group of window manufacturing members of the BWF who saw the only way to fight back against the spread of PVC-U windows was to develop a new, higher standard of wood windows and promote them to the market. To give buyers confidence, all windows accredited under the Scheme are independently tested and audited to ensure they comply to this standard, and Scheme members offer a series of warranties to back them up.

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.

The Kitemark

In addition to meeting the Scheme's technical criteria, manufacturers have to gain BSI Kitemark certification for their factory glazed timber windows, 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 Wood Window Alliance

Forty of the UK's biggest names in wood windows came together in September 2007 to form the Wood Window Alliance, dedicated to the development and promotion of high quality, high performance, sustainable wood windows. The Wood Window Alliance brandmark is your guarantee that a window meets independently audited quality and performance criteria.

To earn the right to become a member, a manufacturer must make windows which:

• Meet the minimum standards set out in BS 644, the main British Standard for wood windows, or equivalent standards from other countries
• Meet the performance standards for wind and weather resistance of BS 6375 Part 1
  
• Meet the minimum performance standards for operational aspects of BS 6375 Part 2, or equivalent standards from other countries
  
• Are accredited by an independent UK or European body to prove compliance with those standards
  
• Are manufactured from timber, sourced legally from sustainably managed forests
  
• Have service life warranties for durability, paint life, ironmongery and insulated glass units
  
• Meet or better the UK Building Regulations recommendations for energy efficiency

While the Wood Window Alliance provides marketing promotion, the TWA Scheme provides one of the most rigorous and best supported of the UK certification schemes for wood windows.

Please visit www.woodwindowalliance.com for more information on the Wood Window Alliance or to join.