Agenda - Planning Commission - 10/04/2007

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Cluster Development: Modern Application of an Old Town Form By Stuart Meck, FAICP Residential cluster development is a form of land development in which principal buildings and structures are gro.uped together on a site, thus saving the remaining land area for com- mon open space, conservation, agricultur~, recreation, and public and semipublic uses. AU images by Randall Arendt Adapted from PAS Report 523/524: Crasroods., Hamlet, Village, Town: Design Charoderistics afTroditionallUeighborhaads., Old and New; revised edition, 2004- In many respects, cluster development dates back to one of the earliest town rorms. In primitive early settlements, dwelling units were often organized to rorm a common area or enclosure that residents could use together and readily defend if necessary. In the United States, the 1928' develop- ment of Radburn, New Jersey, represented the first formal introduction of the cluster devel- opment concept. It drew on English town plan- ning principles, notably those orthe Garden Cities movement. In Radburn, single-family homes and garden apartments ,are sited in "superblocks" or 35 to 50 acres. The super- blocks have no through traffic and are inter- spersed with parks and related green spaces on which the residences face. Clustering also became the basic site design concept in such contemporary new towns as Reston, Virginia, and Columbia, Maryland, Cluster development has a number or dis- tinct advantages over conventional subdivision 60 development. A well-planned cluster develop- ment concentrates dwelling units on the most buildable portion of the site and preserves natu. ral drainage systems, vegetation, open space, and other significp.nt natural reatures that help control stormwater runoff and soil erosion. The commor areas function as a trap for nutrients dissolved or suspended'in stormwater runoff. Cost savings during construction are achieved by the reduction in street lengths and utility installations. Later savings can be realized in street and utility maintenance Gess surface area that needs repaving and ,fewer feet.of water and sewer line tq maintain). Because dwelling units are placed doser together, refuse and other service vehiicles do not have to negotiate over as much str~et mileage, thus reducing travel time. Where cluitering'is accompanied by higher-density r~sidentialland uses and the provision of pedestrian pathways and bike- ways, especiall~ those that link to off-site activity centers, residents orthe cluster devel, opment may walk and exercise more. Clustering also enhances the sense Dr community, allowing parents petter supervision or children playing in common areas and pro- moting social interaction among neighbors. The model ordinance featured in this issue of Zoning Practice is intended to encourage developers to use cluster devel. opment as an alternative to conventional lot-by-lot development, and authorizes clus- ter development as of right either in all resi- dential districts or in selected ones. Section 110 of the ordinance (see page 7) also offers density bonuses of up to 25 percent when a developer: (a) provides affordabie housing as part orthe cluster development (thereby helping the local government achieve hous- ing goals that may have been established by the state) and (b) conveys land ror open space, recreation, or other purposes that is accessible to the public. ZONING?RACTlCE 8.07 AMERICAN PLANNING ASSOCIATION I page 2