Commercial Windows
Draughtproofing existing sash windows
When specifying draughtproofing for existing sash windows please consider the following wording to avoid the risk of a poor quality imitation system being used:
- An approved draughtproofing system meeting the highest requirements (Class 3) of BS6375 Part 1, 2004 in relation to air leakage which tests to 600Pa – the equivalent of 71mph winds.
- The system must incorporate a two-piece parting bead to facilitate removal and refitting during future painting.
- The replacement parting bead section must be available in a variety of colours to suit the chosen paint colour for the windows.
- The draughtproofing system shall incorporate a Sash Removal System including cord brake and housing, to allow sliding sashes to be removed internally for future painting and maintenance.
- Energy performance of the windows to be no less than 80% of that achieved by a double glazed unit.
2 Sample Specification
New sash windows
When specifying new sash windows please consider some or all of the following:
- New sash windows by Bolger Sash Windows
- Frames & sashes to be manufactured in Accoya® wood
- Windows to be guaranteed for a minimum of 50 years against rot
- Windows to be manufactured to traditional details including pulleys, cords and weights, fork jointed meeting rails, and having all dimensions and mouldings to exactly match the original windows / neighbouring properties / to exactly replicate all details found in typical properties from the same period / to exactly match architects details.
- Spiral or spring balances will not be allowed.
- Pinned on meeting rails will not be allowed.
- New windows to incorporate Ventrolla or equal approved. (see above).
