Greening Our Cities: An Analysis of the Benefits and Barriers Associated with Green Roofs

This document investigates green roofs as one piece in a larger strategy that should be taken to maintain the health of the natural environment and the quality of life experienced in Portland. By adding more greenspace to urban areas, green roofs have the potential to bring substantial benefits to our community through mitigating some of the negative impacts of development. The conclusion reached regarding the feasibility of a widespread implementation of green roofs is that the barriers are not insurmountable (with the exception of retrofitting cost for intensive roof gardens in some cases). What is lacking, beyond a need for the dissemination of information, is public policy that reflects the broad spectrum of benefits that green roofs offer. Currently the City Of Portland’s green roof policy amounts to a floor-area bonus meant to encourage the provision of roof gardens in the central city. However, the bonus is narrow in scope and has not been successful in achieving even its limited purpose