A disused garage can be transformed into an apartment and thus enjoy its benefits. You can rent it or if you do it at your parents’ house, you can have your first apartment there, without having to spend so much. One of the decisions that you should most consider is what you are going to do with the big prefab garage apartment door. The easiest thing to do is to leave it and use it as an entrance door, but in truth, it gets complicated when it is a drawbridge, since when you open the door, your entire apartment will be exposed.
The floor of the prefab garage apartment is usually somewhat inclined so that the water drains better, therefore, it is better to take a level and see how serious the slope is. If you want to solve it, you will have to hire someone to level it with a concrete subfloor. If you cannot afford the placement of ceramics or wooden floor, painting the concrete with matt glaze is a good option.
If it is a prefab garage apartment for a car, the walls should remain the same, unless they do not have any type of insulation, which should be placed to avoid cold or heat. But if it is a double or triple, you can also add a wall that separates the rooms, and you can even have your kitchen separate, always considering the option of making windows where you can.