The OP is looking for lock suggestions for peace of mind. It always makes sense to take some steps to secure something you think maybe a temptation.
I assume you are talking about the heavy duty steel roll up doors. That would be tricky to lock from the outside other then some good heavy duty locks on whatever hardware you choose.
I wonder if the garage has power? something tells me no. But if it does, needless to say, well made POWERFUL motion spotlights out of reach above all points of entry will certainly make even someone who can defeat the locks uncomfortable spending the time to do it if they are lit up like the Empire State Building by the spot lights.
If the garage has no power, for less then $1000 maybe less then $500 you can get a commercial type of solar motion spotlight set up someplace with powerful lights... Im not talking about the cheap ones sold at Home Depot but who knows, if you check Home Depot and Lowes online they may have better ones.
Also you can buy some fake cameras or even real cameras that maybe non working on ebay and mount them above any entry points as an added deterrent, just the sight of them with the spotlights blaring in their eyes and the locks should be a deterrent.
Anyway, without a photo and knowing what type of doors, structure of the building, height on the building, whether or not there is power its hard to be specific but these are my thoughts.
As far as someone discouraging you from adding security measures I would ignore, yes, sure anyone can break into anything but not every thief is a rocket scientist, most aren't and others would be to lazy to try to defeat what I just typed and they would just move on. If they didnt, they could just pull the whole thing down with a truck or smash a stolen vehicle through it. Which we know isnt going to happen unless someone knows for sure there is something very valuable in there.
Ive seen a lot over the years, done with that industry now, but heavy duty locks, BRIGHT lights, cameras (whether real or not doesn't matter) and cleared brush/trees/bushes/open views are very discouraging.
... and heck, If you have anything of value in there, hide an apple air tag in it for the heck of it if you use an iPhone. Four of them only cost $100 or $30 each/something like that. We have one on our dogs collar!
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Of course I believe in security systems but honestly, in this case your really trying to prevent someone from getting into a garage, grabbing what they want and running. As you posted that maybe down the road someday but the other above steps I think will prevent most all problems and if it doesnt a security system might just alert you that it already happened. (past tense) You could put up some official secutry system stickers or signs, also sold in ebay. Search adt security sign, vector security sign, vector signs are made of metal and will last longer, also a well known to professional thieves company. Heck they even secure Lowes home improvement stores.
www.masterlock.com
