Building permits have to be secured if you want to build a garage. The plans have to be submitted which will be examined if it conforms to the local laws and requirements on safety and environmental concerns. The building rules of a major metropolitan area are different than more remote and spacious locations.
When building a garage, you should talk to your neighbours and alert them about the noise and various activities that may affect the immediate neighbourhood, like trucks unloading materials and strange men walking about your yard. Your new garage may also affect the landscape or block your neighbour’s windows.