Security Screen (Hinged/Swinging)

A hinged security screen is a narrow stile door with a second door immediately behind it. Both facts constrain the lock: the body has to fit the screen stile, and the internal escutcheon has to clear the main door leaf when the screen closes. Measure the clearance before anything else.

The clearance measurement

With the screen closed, measure the gap between the back face of the screen stile and the front face of the main door. That gap has to accommodate the internal escutcheon and any protruding thumbturn.

Clearance	Practical outcome
Under 10 mm	Very restrictive. Most smart screen locks will not fit
10 mm to 20 mm	Slimline internal escutcheon only. Check the model's published depth
20 mm to 40 mm	The usual working range for purpose-built screen door smart locks
Over 40 mm	Comfortable. Wider product choice

This is the measurement people skip. A lock that fits the stile perfectly can still be unusable because the internal escutcheon fouls the main door. How to measure screen door clearance.

Screen door or main door?

Screen only - the main door stays untouched, which suits rentals and heritage doors. The screen becomes the security layer in daily use.
Main door only - the screen keeps a conventional lock. Simplest, but you unlock twice.
Both, with dual unlock - one credential releases both doors in a single action. Requires matched products and adequate clearance.

Dual unlock is genuinely useful on a daily-use entry, but it is a product pairing rather than a feature you can add later. Products that support dual unlock.

Measure and record

Screen stile width, measured across the face
Clearance between screen and main door with the screen closed
Screen door backset, often smaller than residential timber
Whether the mesh is a security grade product with a structural frame
Hinge side and swing direction

Related categories

Regular Front Door · Door with Narrow Frame · Sliding Screen and Glass · External Gates

Common questions

Should the smart lock go on the screen or the main door?
On the screen if you want to leave the main door untouched and the screen is a genuine security product. On the main door if the screen is decorative or the clearance is too tight. Dual unlock covers both where the products support it.

Will fitting a smart lock void my security screen certification?
It can, if the screen is certified to a security standard and the lock is not the one specified for it. Check with the screen manufacturer before drilling a certified frame.

How much clearance do I need?
Twenty millimetres or more is comfortable. Between 10 mm and 20 mm you are restricted to slim internal escutcheons. Under 10 mm, most products are out. Screen clearance in Chapter 02.

Guides and reference

Check screen door clearance · Dual unlock explained · Ch 04 - Screen doors