Materials specification for Juliet balcony railing:
Bottom bar from 40mm x 8mm flat steel,
top rail from 40mm convex bar (13mm in the centre 6mm at edges), so as to provide a more natural feel .
Upright bars from 12mm round.
Side fix bar is from 40mm x 8mm flat with multiple fixing points.
Projection from the wall is usually 80mm from wall to inside of the Juliet balcony railing, to allow clearance for door handles and sill on door.
Gaps between bars no larger than 100mm as per building regulation requirements.
Height 1100mm high as per building regulations (unless otherwise required)

For brick fixing, the metal Juliet balcony railing should be a minimum of 300mm wider than the door size. to ensure a good fixing.
For a tile hung fixing its likely to be about 100mm wider than the door size (tile hung is subject of an extra charge of £35 for additional work required)

Price guidance