Zoning is, at its core, the municipal regulation of the use of land.  Today, a municipality regulates the use of land by implementing a zoning ordinance.  However, as far back as the 18th century, land use regulations were enacted in Pennsylvania.  Early land use regulations in Pennsylvania and elsewhere were generally concerned with preventing the spread of fires.  For example, an act was adopted in the 1700s that prohibited baking and barrel making except in shops or places built of masonry.  After the Revolutionary War, a law was adopted that prohibited storing more than 30 pounds of gunpowder within two miles of Philadelphia.  The concept of setbacks (i.e., the required distance between a structure and a property line) was implemented to provide for adequate distances between buildings to prevent the spread of fires.

Lower Merion Township was the first municipality in Pennsylvania to adopt a zoning ordinance. However, the ordinance was subsequently challenged, and the Superior Court found in 1925 that the Township did not have the authority to adopt the ordinance.  In the Euclid case decided the following year, the United States Supreme Court held that zoning is a constitutional exercise of the police power.

The police power is a concept that is central to zoning.  It is an inherent power of the state to protect and promote the public health, safety, morals and general welfare.  Most zoning laws, however, are enacted at the municipal level rather than the state level.  Accordingly, states delegate the authority to regulate the use of land – a police power – to municipalities through zoning enabling acts since municipalities only have the powers granted to them by the state.  In Pennsylvania, the enabling statute that gives municipalities the authority to regulate the use of land is the Pennsylvania Municipalities Planning Code (MPC).  The MPC was enacted in 1968 and authorizes municipalities across Pennsylvania to adopt zoning ordinances for the purposes set forth in the MPC.  However, not all municipalities in Pennsylvania have adopted a zoning ordinance.

Pennsylvania has 67 counties and 2,561 municipalities.  According to the Pennsylvania Department of Community and Economic Development (DCED), as of 2015 approximately 68% of all municipalities in Pennsylvania had zoning regulations.  Of the 1,739 municipalities with zoning, 137 of those municipalities had not adopted their own zoning ordinance and were under a county zoning ordinance.  That left 822 municipalities without any zoning regulations.  Municipalities without zoning tend to be more rural, less developed and less populated than municipalities with zoning.  DCED found that as of 2015, 98.2% of Pennsylvania’s urban population was zoned while only 68.9% of the rural population was zoned.

Although the number of municipalities in Pennsylvania that have adopted zoning ordinances in the fifty years since the enactment of the MPC is somewhat surprising, there is no expectation that the municipal regulation of land will decrease.  Rather, it is expected that the municipal regulation of the use of land will only continue to increase and become more extensive.