Study Guide Ch. 6 Site Design Process Flashcards
Site design
Means of implementing broader sustainable design principles
Site design should always balance social/cultural, environmental, and economic considerations
Site design should look to accomplish the following objectives whenever possible
- protect the environment from unnecessary impacts (e.g., soil, air, water)
- restore environmentally degraded areas (e.g., habitats, soil, air, water)
- reuse already developed sites (e.g., shopping centers and brownfields)
- build compact, distinctive, walkable places (e.g., smart growth)
- conserve resources (e.g., use of energy, water, building materials)
Form-based code
Type of land development regulation that uses the physical form of the built environment as its primary organizing principle.
Used to promote high-quality urban design and - unlike zoning - are not oriented around controlled allowed uses within a given area
Floor Area Ratio
FAR
Establishes the ratio between the gross square footage of a building and the size of a lot
1-story bldg covering 50% of a site would have FAR of 0.5
2-story bldg 50% FAR 1.0
1-story 100% FAR 1.0
4-story 50% FAR 2.0
Mixed-Use Development
Health, safety, welfare above all else
Benefits of Mixed-Use Developments
- provide a distinct sense of place
- encourage sustainability via efficient, high-density development
- mixed uses caters to a diverse public
- density encourages pedestrian activity and use of public transit
- create active public spaces
- greater public safety due to increase in site usage
- conducive to urban in-fill redevelopment and re-use of historic structures
Challenges to Mixed-Use Development
- zoning ordinances typically discourage mixed uses
- require complex financing when compared to traditional development
- increased project complexity
- require extensive interdisciplinary coordination
- may entail a more extended or complex development approval process
Transit Oriented Development
TOD
Encourages mixed-use, high-density development in areas surrounding multi-modal transportation hubs.
TOD principles state this developments should be located within 1/8 mile of transit hubs in downtown areas, and a 1/2 mile radius around mass transit stations in all other conditions
Note that the area within 1/4-mile of a transit hub are considered to be the “primary” area for TOD developments, with areas between 1/4 to 1/2 mike considered to be a “secondary” area for development.
TOD principles
- encourage high-density development
- mitigate urban sprawl
- mix commercial/office and residential areas
- provide housing for all price ranges
- reduce parking requirements
- encourage use of public transit
- create walkable communities and active public spaces
TOD complexities
Require significant planning and coordination to execute
Initial research conducted by the design team should establish how the TOD can be integrated into an existing community, the partnerships necessary to create the TOD (e.g., public-private partnership between a property developer and a public transit agency), as well as how the project will be financed
Because TODs are a non-standard form of development they often necessitate the use of design guidelines. These are used to dictate the character of key design elements, thereby helping to foster a sense of place and leading to safe and active public spaces
Cluster Development
Do not increase development density on a site
Take the total number of development units allowed on a site and group these units into clusters of greater density, thereby preserving open space
Cluster developments will sometimes be awarded a density bonus to encourage cluster-style development
Benefits of cluster development include
- preservation of open space and site character
- protection of critical natural and cultural/historic resources on a site
- reduction of impervious surfaces across the site
- lowered construction costs for streets, utilities and other infrastructure
- reduction in site disturbance/grading
- reduced visual impact of existing communities
Conservation Development
Analogous to cluster developments
Focuses development on each parcel as it is being planned so at least 50 percent of the buildable land is set aside as open space. The same number of homes can be built in a less land-consumptive manner, allowing the balance of the property to be permanently protected and added to an interconnected network of community green spaces. This “density-neutral” approach provides a fair and equitable way to balance conservation and development objectives
“Conservation subdivision”
Characteristics unique to conservation developments
- begin by identifying primary and secondary conservation areas on a given site
- primary conservation areas comprise lands where development is not typically permitted (e.g., wetlands, floodplains, and slopes exceeding 25 percent)
- secondary conservation areas comprise any other significant cultural and natural features located on site that should be preserved
- the process of identifying primary and secondary conservation areas is known as “conservation mapping”
- after identifying areas for conservation, the remaining part of the property becomes the potential development area
Planned Unit Development
PUD
Although sometimes included as part of zoning regulations, planned unit developments are often framed as a variation of traditional zoning practices or “rezoned” special districts
A tract of land that is controlled by one entity and planned and developed as a single development (at once or in stages) over a relatively long period of time (generally between 5-15 years).
Allow the consolidation of multiple parcels into a single master-planned project, often for mixed-use development.
Provide the greater flexibility in meeting the density and land use requirements for the site as a whole and - as such - allow for the protection of environmentally sensitive areas and the creation of walkable neighborhoods, among other benefits
Greenfield Sites
Sites that have not been previously developed or extensively graded, or land that is currently being used for agriculture.
Typically provide a variety of ecosystem services, including reduction of stormwater flows, improvements to air and water quality, food production, habitat, and cultural and natural preservation.
Development on greenfield sites should be discouraged whenever possible.
Examples include agricultural fields, pastureland, park lands, and conservation areas.
Brownfield Sites
Any previously developed land that is not currently in use, with any redevelopment complicated by the presence or potential presence of a hazardous substance, pollutant, or contaminant produced by past site users.
Estimated over 450,000 brownfields in US.
All brownfield sites require a Phase 1 environmental assessment (prior to sale of the property) to determine the past and current site ownership and to identify if any activities took place that would have resulted in site contamination.
Phase 2 study is required to determine the location and remediation of contaminants on site and to establish if future land use restrictions are required.
Development of a brownfield site is therefor a (potentially) complicated process.
Benefits of brownfield development
- ecosystem restoration
- protecting and improving public health (via contaminant reduction)
- economic development and job growth
- increasing property values
- creating community amenities and services
- reuse of existing infrastructure
- reduced urban sprawl
- often located adjacent to public transit routes
Challenges to Brownfield Development
- extent and location of contamination
- unclear costs and risks to the public and to the property developer
- condition of existing structures on site
- potential lack of access to public infrastructure
- lack of clear ownership/title to land in question
- property market conditions (i.e., many brownfields are located in economically depressed regions)
Greyfield Sites
Underutilized or abandoned retail and commercial properties located in urban and suburban areas, and they are typically characterized by large commercial buildings surrounded by parking lots and little or no vegetation.
Although development on greyfield sites can be more costly than greenfield sites, greyfield as are associated with numerous environmental and economic benefits
Greyfield development benefits
- ecosystem restoration
- economic development and job growth
- increasing property values
- creating community amenities and services
- reuse of existing infrastructure
- reduced urban sprawl
- often located adjacent to public transit routes
- highly adaptable to accommodating new uses
Urban Infill
The practice of developing vacant or underutilized properties within an existing community or urban area, and it is typically more complex and costly than developing a greenfield site.
Note that urban infill projects are most successful when they respect the context of their surrounding neighborhood. As such, infill projects should attempt to match the massing, scale, proportion, or other design attributes of nearby buildings to the greatest extent possible.
Benefits of Urban Infill Development
- neighborhood revitalization
- greater sense of community
- economic development and job growth
- providing housing near jobs and services
- adjacent to existing infrastructure, including public transit
- increase the provision of community services and amenities
- decreasing automobile use (i.e., less traffic, pollution, carbon emission reduction)
- transit-oriented development and walkable neighborhoods
- increasing property values
- reduced urban sprawl
- remove/mitigate potential safety hazards
Challenges to Urban Infill Development
- restrictive zoning practices that conflict with mixed-use or other redevelopment strategies
- expensive infrastructure upgrades may be required
- parking requirements may be difficult to meet due to existing development patterns
- community opposition to development impacts (e.g., increased traffic from new site users)
- financing may be more difficult to obtain if a project is complex or unique