Hi,
I didn’t mean to imply anything negative by ‘pet project’. Rather I meant that if you were not on the SC, offering to do more than just suggest something to others is a good strategy to get things done. As general advice I tell people that if you make the running on the project you are keen to see done, others are likely to appreciate that, leave you to it, and support whatever recommendation you come up with, so long as it is clearly well researched.
If the doors are poor quality, it might be better to just replace them with better door that will self-close and lock. Perhaps talk to a few security installers and ask for their recommendation. I expect yours is not an unusual situation.
One thing to perhaps ascertain: Do people leave the doors unlocked out of laziness because they need to use a key or do something more than just walk through? Alternatively, do they leave them unlocked deliberately because it is easier for visitors to be able to come directly to their unit door or because they can come and go without fishing out their keys from bags or pockets? Would an improved system be subverted by people chocking the doors?