The cost of a professional El Cajon garage remodeling service will depend on what you want the space would turn out to be, either you want to transform it into an office workspace, a small apartment, or a master bedroom with its own bathroom. There are even more El Cajon garage remodeling projects aside from the ones mentioned and the possibilities are endless. You can add new windows and a new entry door to the space but take note that they will affect the cost of the service.