Nonconformities
For example, an auto repair garage may have existed before the Borough adopted zoning. It is located in a residential district. It may be changed to a store, which would be less intense. However, it could not be changed to an asphalt plant, which would be more intense.
Likewise, in most cases, existing vacant lots that were legally established may be built upon – even if they do not meet the minimum size requirements of a zoning ordinance. However, any building would still need to meet setback, wetland and floodplain regulations.
However, if a use was not legal when it first started, it has no right to continue. For example, if a house was illegally converted into apartments twenty years ago, it is still illegal, and can be required to be deconverted.