Builder keeping extra keys to new house build

Located in Victoria. We’ve just moved into our newly built house. We were generally very happy with the builders, apart from being slow to fix a few minor defects they were very professional and did good work.

We have paid them, received keys, everything is completed paperwork wise and we’re in the three month period where we spot any issues and they’ll resolve them at the end.

In the course of resolving an issue (they turned up when we weren’t home to fix something and via text message asked if they could use their ‘master’ key to enter) we found that they keep a set of master keys to sliding glass doors, allowing access to any house they have built using these doors.

The contract very clearly states that all keys will be handed to the owner once payment is made, but as these are keys to all the doors used in houses they’re unlikely to give them to us (nor would we want them of course). I see no reason they would need these keys and we feel it’s unsafe and totally unacceptable that keys to our house (and others) are sitting in their office.

We’ve requested they rekey these doors at their expense with unique keys and give them to us, but what’s the next step if they refuse?