Denver’s Denver Green Roof ordinances requires the construction of green roofs for new buildings over 25,000 square feet, and for existing buildings at least 25,000 square feet when the building requires a roof replacement. The code defines a green roof as an extension above the roof, which allows vegetation to grow. The portion of the roof required to be dedicated to green roofing increases along with the gross square footage of the building. For example, a 25,000 square foot building must be covered by 20% green roof, whereas a building with 200,000 square foot or more must be covered by 60% green roof. Owners may combine solar paneling and green roofing to meet the requirements. The ordinance further creates a green roof technical advisory board, which is composed of experts in green roofing and advises the city planning board on green roof issues. The planning board and technical advisory board also promulgate guidelines for the construction of green roofs, to assist developers in complying with the ordinance.

The ordinance imposes penalties for property owners that forego construction of green roofs for buildings that received a permit to build after January 1, 2018. If a property does not comply with the requirements, the owners or occupiers thereof are subject to a fine of no more than $999 per violation, or imprisonment for a maximum of one year per violation. A violation occurs every 24 hours that the property is out of compliance with green roof requirements. Voters approved these measures by referendum, hoping to reduce urban heat island effects, provide habitat for bees and other wildlife, and reduce GHG emissions. Notably, the requirements are not imposed on residential buildings less than 4 stories or 50 feet in height, or greenhouses and their related structures.

To view the provision see Denver, CO, Code of Ordinances §§ 10-300 to 10-308 (2017).

To view the full SDC brief on Green Roofing see Green Roofing.