Upzoning refers to the process in which a building is promoted to a higher level of use. Sometimes an owner will be asked to sell their residence so that a company can upzone it into a commercial business. One's home could also be turned into a custom business through upzoning. Various offices and establishments are run through a person's home in such a way. Upzoning can also refer to a city's efforts to modify and reform current buildings that are considered sub par or run-down. In this context, upzoning can also refer to increasing the efficiency of subway networks and replacing components of factories to cut back on pollution. Upzoning is essentially a form of investment. While decreasing negative effects on the environment, effective upzoning can make great strides in bolstering the local economy.