Protected trees
According to the city Heritage Tree List (revised August 2013), Heritage trees under Section 14-705 of the Philadelphia Zoning Code, which applies to development on existing lots greater than 5,000 sq. ft. Heritage trees are listed species (for example red, sugar and silver maple, oaks, hickories, American beech, black walnut, tuliptree, sycamore, American elm) that are 24 inches or more diameter at breast height. Any American chestnut of any size counts as a Heritage tree. They may not be removed without a special exception approval. Site clearing (including cutting or removing trees) on lots over 5,000 sq. ft. needs a zoning permit; single-family, two-family and urban agriculture lots are excluded from that permit.