The Noise Insulation Regulations 1975

Specification for Venetian Blinds

5.—(1) A venetian blind, where fitted, shall be placed between the panes of double windows, and the following conditions shall be complied with—

(a) the slat surface shall be white or near white;

(b) the ratio of width to spacing of slats shall be between 1.15:1 and 1.25:1;

(c) the blind shall have horizontal slats capable of being raised or lowered, and the angle of tilt of the slats shall be adjustable, 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 tilting mechanisms at either end of the blind box;

(d) the controls specified in sub-paragraph (c) above shall, where practicable, be readily accessible within the room with the windows fully closed;

(e) the opening for control cords shall be sealed or kept to the minimum necessary for smooth operation;

(f) the blind box shall be fitted to the top window reveal or framehead between the panes of the double windows; and

(g) the length of the slats shall be between 10 millimetres and 30 millimetres less than the width 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.

(2) Where it is not practicable to comply with any of the specifications in this paragraph the most practicable alternative specification may be used.