The provisions in relation to letter plates are outlined in Technical Guidance Document D of the Building Regulations. Regulation D2 states that “A letter plate aperture shall be so positioned at a reasonable height above ground level so as not to endanger the health and safety of persons using such apertures.”
The height and width of the aperture of a letter plate should be 250 mm and 38 mm with a tolerance for the height of +/- 10 mm and for the width +/- 1.5 mm. I.S. 195: 1976 Letter Plates should be adhered to when designing, manufacturing, and installing letter plates.
Diagram E11 - Letter plates
