Old G. James sliding glass door with the glass on the outside — can the lock be upgraded, or only replaced?

Our answer

This is an old G. James aluminium sliding door, and it has been fitted the wrong way around: the glass door is on the outside and the screen door is on the inside. Glass is usually inside and screen outside. A lot of Brisbane homes from the 70s and 80s were done this way, and it decides which lock you can have.

The G. James doors from that era sit very close together, so there is almost no gap between the glass door and the screen. The only lock that fits in that gap is the one already on it — the Whitco low-profile sliding door lock.

So it comes down to why you want it replaced. If you want a bigger or better lock, it can't be done: there is no room between the two doors for anything larger. If the lock is worn out or broken, we can replace it like for like, and the new lock can be keyed to your existing key so nothing else on the ring changes — or it comes with two new keys.

The rule of thumb for these reversed G. James doors: the gap between the doors picks the lock, not the catalogue.

Real quote, September 2026: $352 inc GST — callout and a replacement Whitco low-profile sliding door lock, keyed to the existing key or with two new keys.