What did Penn do to encourage low population density?

He distributed land in large plots

Pen looked with disdain on London's crowded conditions and sought to prevent this in the colony. He hoped that the people residing in the colony would have a family garden. To encourage low population density, he distributed land in big parcels

While establishing the capital of Pennsylvania, Penn decided that such city couldn't be like London's crowded conditions or any European city with complicated urban life due to over-population and poor administration. He took upon himself the tasks of designing and administering the city to prevent this.

He designed the city with very wide streets and five major squares. He liked the idea of combining city and country. He wanted to keep businesses and houses apart from each other because he hoped that every resident would have a family garden. He chose the site carefully, as Philadelphia is situated at the confluence of Schuylkill and Delaware rivers. Penn plans were that the Delaware River would supply the needed outlet to the Atlantic and Schuylkill would be an artery into the interior of Pennsylvania.