Low-Density Housing: Low density housing promotes better quality of life, less pollution due to less density, and easier builds. However, they are expensive and cause pollution due to driving.
Medium-Density Housing: There are some improvements in quality of life and some reduction of pollution. Medium density housing is more affordable.
High-Density Housing: High density housing has a lower quality of life due to sacrificing privacy, living space, etc. There's higher pollution, pollution due to driving is lower however. The cost of living is much cheaper.
Zoning Laws: Zoning laws are regulations that define how property may be used.