DuPage County, IL Tree Protection: Parkway Planting (2026)

Under Sec. D of the DuPage County Code, any new subdivision approval carries a mandatory street tree requirement: the subdivider must plant shade trees within five feet (5') of the right-of-way or utility easement of all streets within and abutting the subdivision, or, at the Highway Authority's discretion, within the established utility easement. The planting ratio is fixed at one tree for every 40 feet of frontage along each street. The Plat Committee can waive the requirement, but only where existing trees already along the right-of-way or on abutting property meet the regulation in the Committee's opinion; a bare request for a waiver without qualifying existing trees will be denied.

Every tree planted to satisfy this section must have a minimum trunk diameter of two and one-half inches, measured twelve inches above ground level, so undersized whips do not count toward compliance. Enforcement of the section runs through the DuPage County Building Code rather than a separate tree ordinance, meaning a subdivider who skips the planting can be held up at the building permit and final acceptance stage. This sits inside Article V of Chapter 31 (Subdivision Regulations), alongside sidewalks, bikeways, street lighting and street signs, so it applies at the platting stage for new residential and commercial subdivisions in unincorporated DuPage County rather than to existing built lots. The same subsection also carries a list of prohibited tree species that may not be used to satisfy the planting requirement.