Overview
An inside L-frame fits within the opening and leaves the front of the wall or architrave exposed. It can preserve decorative trim, but it also leaves the perimeter fitting gap visible. Confirm usable depth and opening squareness before selecting it.
What is an L-frame?
An L-frame has a right-angled cross-section. Inside and outside versions have different fixing positions and profiles: the inside version sits in the reveal, while the outside version carries the shutter in front of the opening. Select the version that matches the mounting method.
What is an inside mount L-frame?
The inside L-frame fixes to the inner faces of the recess without covering the front of the architrave. It can sit near the opening edge or further back where depth permits. This can preserve decorative trim, although the perimeter gap remains visible rather than being covered by a Z-frame lip.
How does an inside L-frame mount to my window?
Allow 70 mm of usable depth for an inside L-frame with freely rotating blades. Measure from the proposed front position to the nearest projecting hardware, not just to the glass. Check that the window and shutter panels can both open before finalising the fixing position.
Can I install an L-frame with an architrave?
An inside L-frame leaves the architrave visible, which is useful with detailed mouldings. It needs a suitable recess and can show perimeter gaps more clearly than a Z-frame, especially on an uneven opening. Check all widths and drops before choosing this appearance.
Can I install an inside L-frame with a window sill?
The bottom frame can rest on the sill while the remaining sections fix inside the recess. Measure the drop to the sill surface at the intended frame position. Check that the ledge, taps or nearby fittings do not obstruct panel movement.
