The short answer
Most grilles use a lock box on the leading edge with a key-operated cylinder, sometimes with extra shoot bolts. Windows needed for escape use quick-release locks with a keyless internal lever. Some grilles take padlocks instead.
What is a lock box?
A steel housing on the closing edge of the grille that contains the latch or bolt and a cylinder. Key from one or both sides depending on how the opening is used.
When are extra bolts used?
Wide grilles and gates often have shoot bolts into the floor and head to hold the leaves in line and resist levering.
What is a quick-release lock?
A lock with a lever or push release on the inside face that opens without a key. It is the right choice for grilles over escape windows.
Can locks be keyed alike?
Yes. Cylinders can be keyed alike so one key opens every grille, or arranged on a master-key suite for businesses.
This guide is general information, not legal advice. Rules differ between England, Wales, Scotland and Northern Ireland; check with your council, building control or insurer where it matters.
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