Disclosed is a modular building system including, in some embodiments, one or more wall panels, one or more floor panels, and one or more roof panels. The modular building components of the modular building system including the one or more wall panels, the one or more floor panels, and the one or more roof panels can form housing or storage structures with electrical wiring, plumbing, or both wiring and plumbing. The housing or storage structures can be erected by one or more persons without a need for a plumber, an electrician, or power tools. Also disclosed is a method for erecting one or more housing or storage structure in accordance with the modular building system.