Potential fire behaviour and various societal benefits (air pollution removal, carbon sequestration. and stormwater runoff) were quantified in a California Sierra mixed-conifer forest in (a) untreated conditions, (b) after removing all understorey trees <15 cm dbh, and (c) after thinning 50% of the stand's total basal area. Potential fire behaviour was modelled under constant conditions near a hypothetical development by the FARSITE fire behaviour and growth simulator and societal benefits were calculated by ClTYgreen, both OIS-based software applications. Results showed that fire behaviour was considerably moderated by both thinning treatments. Modelled societal benefits, however, were largely unaffected by either treatment, which maybe the result of inherent assumptions in the model. Critical elements of sustainable development in the wildland-urban interface are discussed, including fuels management, enforceable construction standards, sound land-use planning, community education, and appropriate suppression resources. Each of these components will vary depending on the ecosystem and socioeconomic conditions of a given area that is under consideration.