4. While a strong master plan sets the stage for woodland conservation, further steps must be taken to implement the master plan. They are creating and adopting a zoning map and land use regulations. The zoning map shows what type of development will be allowed in each part of the community. Land use regulations guide the design of physical elements like streets and buildings, and can require natural resource conservation as part of land development activity. The master plan, zoning map, and land use regulations work together to produce a comprehensive set of tools to achieve woodland conservation goals. THE ZONING MAP The first step a municipality can take toward preserving critical natural resources is to make sure that the zoning map responds to the natural resource inventory for the municipality. For example, heavily wooded land should be zoned for natural resource conservation or low impact uses whenever possible. The zoning map may include special town center or village center districts that are planned for retail, restaurant, and mixed-use growth. This is the type of development that should be located in places where natural resources are not critical and priority woodlands are not present. Development in environmentally sensitive areas should be zoned differently if the goal is to preserve critical areas. Special zones and overlay districts can help protect environmentally sensitive areas. For instance, a special woodland conservation zone may be appropriate for heavily wooded, steeply sloping areas of the town. The woodland conservation zone would have a lower lot density and require that special site design techniques be used for all development in the zone. Or, regulations within the zone may require that a certain percentage of all woodlands be conserved in any proposed development. An overlay district is an optional set of zoning regulations that can be used in addition to regulations for the basic zoning district. For example, a woodland conservation overlay district may provide lot density bonuses if a certain percentage of woodlands on the site are conserved. Once the zoning map and the natural resource inventory are consistent, builders and land developers have clear guidance. This results in a win-win situation where land is developed in accordance with its legal zoning while critical natural resources are preserved. 23
SITE DESIGN TECHNIQUES Another way to implement the Master Plan is to develop land use regulations for each zoning district and performance standards for site design. These regulations should respond to strategies laid out in the Master Plan, like site design flexibility, cluster design, and natural resource conservation. Land use regulations should be fair, predictable, and legal. Some land use regulations inadvertently restrict efforts to save trees. At the very least, municipalities should make sure that land use regulations support the efforts of builders and developers to save trees and woodland resources. Land use regulations are more flexible when they include language that supports variations in performance standards to do so. Inflexible site design regulations that limit the conservation of existing trees include: minimum lot sizes, minimum lot widths, maximum building height, and building setbacks. If site design regulations can be made to provide for a range, rather than fixed width, height, and setback distances, then lots can be designed to respond to existing site conditions. In the past, conventional subdivisions placed all of the land on the development parcel into lots of a fixed size, leaving little ability to adapt development to local site conditions. It is time to move away from this type of inflexible criteria. Residential site design regulations can be written so that they provide a specific lot density for each zone, but allow a great deal of flexibility in how the lots are configured. Lot density is the permitted number of dwelling units per gross area of land to be developed. Two site design techniques that incorporate flexible lot configurations are cluster and lot-size averaging. Cluster site design, also called open space zoning, places a portion of the available land into residential building lots while preserving some percentage of the overall site in open space. Homes are placed on smaller lots but the overall gross density is about the same as a conventional development, unless the community chooses to give a density bonus for using cluster site design. Land not used for building lots in cluster developments is placed in open space and can be owned by a homeowner's association or a government entity. SITE DATA COMPARING STANDARD TO CLUSTER DEVELOPMENT OPTIONS 24
NEW TREELINE CONVENTIONAL SUBDIVISION AGRICULTURAL FIELDS CLUSTER SUBDIVISION A WITH MINIMUM 2-ACRE LOT SIZE AGRICULTURAL FIELDS CLUSTER SUBDIVISION B WITH MINIMUM 1-ACRE LOT SIZE LOT AVERAGING SUBDIVISION WITH VARIABLE LOT SIZES CLUSTER LOT LAYOUT AND LOT AVERAGING HELP SAVE TREES 25
CLUSTER LOT LAYOUT Cluster design does not require that all lots be concentrated in one part of the site, but that they be located such that beneficial open space results. One way to approach lot layout is to delineate areas to be conserved and orient lots in the remaining portions of the site. Lots should be configured so as to maximize lot value and avoid or minimize environmental harm. For example, in a heavily wooded conservation zone, the lot density might be one dwelling unit per five acres of land. That density would allow a total of 20 homes on 100 acres of land. If the 20 allowable homes were built on 2-acre lots, a little over 40 acres of the 100-acre parcel would be used for home construction in a cluster design. The area of land used for homes, plus additional acres required for the construction of roads, utilities, and other amenities will vary, depending on the specifics of the subdivision. But typically, cluster design can result in the conservation of half or more of the original land parcel for designation as an open space parcel. If the same number of homes were constructed on one-acre lots, a little over 20 acres of the 100-acre parcel would be used for home construction, resulting in well over half of the wooded land being conserved. In addition, wooded areas can be left on portions of the building lots not used for homes, driveways, septic areas, or other built features. Municipalities must decide what type of land should be dedicated to open space parcels and what role open space plays in the community. Different areas of the municipality may have different needs. This should be articulated in the development regulations so that areas with a need for active recreation have the opportunity to gain open space parcels that are usable. In areas where conserving woodlands is a goal, development regulations should state that environmentally sensitive areas are the priority for open space dedication. Frequently, developers benefit from a higher lot yield using cluster techniques than conventional subdivision design because of the flexibility smaller lot sizes offer. Each community must decide whether it is appropriate to give builders and developers an incentive to achieve the goal of woodland conservation. Communities should 26
design zoning densities that work with flexible lot design techniques to yield the type and amount of development they want at full buildout. Lot size averaging allows a broad range in residential lot sizes so long as the permitted gross density is maintained. There may be one or two very large lots, 10-acres or 25-acres in size, with the rest of the lots ranging in size from two to four acres. No land is left in separate open space parcels, but lots can be deed restricted from further development. This technique eliminates the need for a homeowners association, which can be advantageous in certain situations, such as very small subdivisions. OTHER FLEXIBLE SITE DESIGN TECHNIQUES Minimizing the width of roadways can also save trees. Street widths in residential subdivision design are regulated at the state level through the Residential Site Improvement Standards (RSIS). But it is possible to allow reduced street widths providing the appropriate procedures set forth in the RSIS are followed. For commercial and office site design, flexible lot design standards are very important. In commercial, retail, and other intense uses, the best strategy is to plan for these uses on land that is not wooded. The best chance for saving woodlands in heavy commercial areas is to save small patches or individual trees. Flexible building setbacks are critical to woodland conservation efforts on commercial sites. For office buildings, the amount of building that can be constructed on a site is usually expressed in floor area ratio. That is, a certain number of square feet of office space is allowed to be constructed for each acre of land. One way to conserve woodlands on these building sites is to allow taller buildings. Putting the office space into taller buildings results in a smaller building footprint, or shape of the building at ground level, and reduces the amount of disturbance to woodlands on the property. Again, it is critical to make sure that the floor area ratios allowed by the regulations yield the amount of office space your community can accommodate. 27 LOT SIZE AVERAGING