A multi-family building structure using light weight prefabricated parallel modular living units is provided. The structure comprises at least first plurality of parallel modular living units and a second plurality of parallel modular living units. Each living unit in the first plurality of living units comprises a first outer and inner modules and a first synthetic residential module between the first outer module and the first inner module. Each living unit in the first plurality of living units comprises a second outer and outer modules and a second synthetic residential module between the second outer module and the second inner module. The structure further comprises a synthetic corridor module formed between the first inner module of the each living unit in the first plurality of living units and the second inner module in the second plurality of living units.