Planopedia

Conservation development is an approach to development that prioritizes the protection of natural resources, open space, and agricultural lands. Among other intentional planning and design approaches, conservation developments cluster housing into a circumscribed area within a larger portion of land available for development, preserving open space, agricultural land, or natural areas as a component of the overall development. 

Conservation development is usually applied to rural, exurban, or suburban residential subdivisions, where local officials and developers have committed to the protection of resources, rather than prioritizing development above all other considerations. Thus, conservation developments try to locate a middle ground between unrestrained sprawl and the restrictions of urban growth boundaries and greenbelts. Where master planned communities or planned unit developments will cover almost every inch of a development parcel with homes, retail, infrastructure, or highly cultivated landscaping, conservation developments will preserve the natural condition of much of the land. And, where urban growth boundaries set aside land to prevent development for the long term, conservation development protects land and natural resources alongside development. 

Conservation subdivisions, one of the most common forms of conservation development, are defined by the protection of a significant portion of the development site as open space, small lot sizes on developed parcels, and development densities specified by a local master plan or zoning ordinance. As a result of this approach, conservation developments are estimated to preserve between 50% and 70% of the buildable land in a project area. 

Researchers Jeffrey Milder and Story Clark studied the prevalence of conservation developments and produced a paper, "Conservation Development Practices, Extent, and Land-Use Effects in the United States," published in 2011 in Conservation Biology, estimating the amount of land protected by conservation developments at 9.8 million acres.

Earlier research by Milder, "A Framework for Understanding Conservation Development and Its Ecological Implications," published by BioScience in 2007, identified two categories and four types of conservation development. Under the first category, "Conservation with Development," Milder included conservation buyer projects and conservation and limited development projects. Under the category of "Development with Conservation," Milder included conservation subdivisions and conservation-oriented planned development projects.

Each of these four types of conservation development share common traits, namely the 1) deliberate protection of land either by a conservation organization or a conservation easement, 2) financing for conservation of the protected land by the development on the rest of the site, 3) a planning and design process that begins with an assessment of the land's ecological features and resources, and 4) varying practices of infrastructure that maintains the sustainability of the site and mitigates the impacts of development on the surrounding area.

The benefits of a conservation development approach can include the protection of biodiversity (especially compared to the negative effects of a sprawling or greenfield development), resilient stormwater infrastructure, a cleaner water supply, and a sustainable approach to growth. 

Many of the specifics of conservation development were formulated in the early 1980s by Randall Arendt, who based many of those concepts on the "design with nature" philosophy created by Ian McHarg.

Because they limit the extent to which developers can maximize the profit potential of a parcel, and in turn limit the property tax revenue generated by the site, the conservation district concept can be a tough sell at the local level. Regulations requiring, or incentivizing, conservation development vary greatly by location. One example of legislation that has produced conservation developments is California’s Natural Community Conservation Planning Act (NCCP). 

In recent years, for example, the growing popularity of "agrihoods" illustrates the marketability of the conservation development approach. The protected land also provides space for popular recreational activities, such as hiking, jogging, and birding. 

Conservation districts can also be sold to local politicians by pointing out the cost savings created by minimizing the amount of costs for the creation and maintenance of infrastructure and benefiting from the passive benefits of landscape stabilization, flood control, and clean water.