Bay Or Bow Windows: Sizes

When measuring your Bay or Bow, please pay close attention to the diagrams as to where measurements are to be taken from and note the information below:

Bay Windows: Measure widths from inside the property and height from outside. Projection/s as shown.

Existing Bow: Measure widths from inside the property and height from outside. Projection/s as shown.

New Bow: Measure widths from outside the property and height from outside. Projection as shown.

New Bow with Canopy: Measure widths from outside the property and height from outside. Projection as shown.

This is for the size in Millimetres (mm) that you would like the window manufactured to. This size is to include any Cill and will be manufactured to tolerances of 2-3mm. Please ensure the sizes provided are not tight brickwork opening sizes as your new window may not fit, always allow a tolerance of about minus 5mm in the width on the two returns and minus 10mm in the height. (Reduce size further if your opening is not square, out of level or has protruding bricks as your new window must be installed square, level and plumb).

Assumptions: The normal width for a side opening sash is 600mm, this is measured from the edge of the outer frame to the centre of the mullion (vertical bar). Exceptions: If the window divides into equal parts of less than 600mm (divided by mulions) then your side opener will be set at an equal division. However, if you specify egress or easy clean hinges it will revert to a 600mm wide section. The normal height of a fanlight sash is 360mm, this is measured from the top of the frame to the centre of the transom (horizontal bar). Georgian bar, diamond and rectangular lead will be laid out according to our best practise.