3. Siting and fitting a windowbox
- A removable box is best for access to the window and ledge for repairs and maintenance.
- Although boxes are heavy and unlikely to be blown away, fix them in place with side brackets or chains if they're on the first floor or higher, for peace of mind.
- For sills that slope dramatically, use wedges (home-made or bought) to keep the box on the level.
- To allow windows to open outwards, support a box beneath the windowledge with right-angled metal or wooden brackets (available in garden centres and DIY shops). Simply drill and plug holes in the wall in order to screw the brackets in position, using a spirit level to ensure that they are correctly placed.
- Or choose a windowbox designed to be suspended from screw heads projecting from the wall. Only suitable for small lightweight plastic boxes, but a row of these beneath a wide window is just as effective as one large container, and easier to lift and move.
