# The Heathrow Airport–London Noise Insulation Grants Scheme 1989, Paragraph 6: Specification for Venetian blinds


Venetian blinds where fitted shall be placed between the panes of double windows, and the following conditions shall be complied with:
(1) the surface of the slats shall be white or near white;
(2) the ratio of width to spacing of the slats shall be between 1.15 : 1 and 1.25 : 1;
(3) the blind shall have horizontal slats, capable of being raised or lowered, and the slats shall be adjustable in angle of tilt, the control being either:
(i) by a single continuous cord operating both the raising and lowering and tilting mechanisms from one end of the blind box, or
(ii) by controls for the raising and lowering and the tilting mechanisms at either end of the blind box;
(4) the controls specified in paragraph (3) above shall, where practicable, be readily accessible within the room with the windows fully closed;
(5) the opening for control cords shall be sealed or kept to the minimum necessary for smooth operating;
(6) the blind box shall be fitted to the top window reveal or frame head, between the panes of the double windows, the length of the slats shall be between 10 millimetres and 30 millimetres less than the length of the recess at its narrowest point, and the blind shall be capable of extending to the lowest level of the glazing of the outer window.

---
Source: https://www.legislation.gov.uk/uksi/1989/247/schedule/paragraph/6 (the official version)
Page: https://openlegislation.uk/heathrow-airportlondon-noise-insulation-grants-scheme-1989/schedule/paragraph-6
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.