Used to keep thieves out, or criminals inside, building locks are an essential thing in maintaining power in your location.
Building locks can only be made out of iron, and require a screwdriver to make. One building lock requires 200 grams of iron, and takes 2 days to make.
When the building lock is finished, the key to it will go to the project initiator's inventory. A key can be copied, with the use of 10 grams of iron and a file
A locked building door cannot be passed without either the right key, or a successful lock-breaking attempt with a crowbar.
Please also note that this reference is in regards to a Building Lock, and not a Vehicle Lock.