Inside L-Frame: Recess-Fit Guide

As you work through the guide, the inside L-frame is a simple L-shaped frame designed to sit entirely within the window recess. Unlike a Z-frame, it does not have a wide lip overlapping the front of the wall or architrave.

In this article

• What is an L-frame?
• What is an inside mount L-frame?
• Can I install an inside L-frame with a window sill?

What is an L-frame?

L-frames are used for both inside and outside mounting, but the profiles are different. This article covers the version designed specifically for an inside recess fit.

What is an inside mount L-frame?

The frame is fixed to the inside surfaces of the recess and the shutter panels hinge within it. Depending on the available depth, it can sit close to the front of the recess or further back.

How does an inside L-frame mount to my window?

For the order, you need enough unobstructed recess depth for the frame of approx 70mm for an inside L-frame, shutter rails and rotating louvres. Measure to the nearest handle, lock, winder or screen rather than to the glass alone.

Can I install an L-frame with an architrave?

Yes. As illustrated above, An inside L-frame is often a great choice with decorative architraves because the shutter stays within the recess and leaves the front face of the trim visible.

Can I install an inside L-frame with a window sill?

Yes. The lower frame section can sit on top of the sill while the side and top sections remain fixed within the recess.

If the window has both an architrave and a sill, the same principle applies: confirm that the recess has enough clear depth and that the sill does not interfere with the shutter panels opening.