What Is An Obstruction?
Obstructions could be inward opening windows or fly screens, which may not be accessible if you reveal fit your shutter. Other obstructions, such as window winders, handles, locks, keys, alarm boxes are fine - as long as you have enough clearance between the end of your obstruction to the end of the recess.
Clearance Required for Reveal fit
As a general rule, 70mm of clearance is required from the furthest point on your window to the edge of the recess for a reveal fit. This is so that the shutter blades can be opened completely without hitting the window pane. However, this requirement is relatively conservative and the exact clearance needed ultimately depends on the type of frame you will be using. In other words, you may still be able to reveal fit your shutter, even if you have less than 70mm between your obstruction and recess.
Managing Obstructions for a Z-Frame
A Z-frame mounts inside the recess and creates a lip around the outer frame. A Z-frame
requires 39mm of clearance to fit inside the recess.
Managing Obstructions for an L-Frame
An L-frame fits inside the recess and can be mounted flush against the wall or sit back from
the wall at any desired depth. An L-frame requires 65mm of clearance to fit inside the recess.
