There is a great effort to secure all residential garages but emphasis is mostly given to those attached to the houses. People would invest more in strong garage doors and locks knowing that perpetrators could have access to the main house. Though, detached garages deserve equal attention, planning the exact location for their construction, reinforced security and garage door repairs. The problem is that many of them are not built at the side of the house, where they can be seen from the main street and people can have safer access, but at the back part.
They may have windows and pedestrian entrances but, above all, people still keep their expensive cars as well as bicycles, tools, furniture, laundries and freezers in there. Consequently, detached garages ought to be well-protected. Don't forget that you might also keep personal stuff, remote controls and keys of other properties in the car and you wouldn't want someone gaining access to your personal life.
It is vital to choose equally strong systems as if there was access to the main house. It is also important to check the door often and never neglect garage door maintenance just because this is the only place you keep the car. Installation of locks will certainly reinforce the security of the place. You can either place them at either side of the garage door. It would be smarter to place bolts from inside, so that perpetrators won't know where to look or how to break the lock. In this case, you can lock the latch and exit from the pedestrian door, which must also be locked properly.
A wireless garage door keypad will also be ideal for quick access but also for locking the door with personal codes. Reinforcing the security in the driveway and the perimeter with cameras, alarm systems and lights is also smart. In fact, detached garages at unseen spots of the house would need more lights and perhaps light motion detectors. So, when you get new garage door openers, make sure they come with light sensors and add more yourself.