DENSITY METHODS & TOOLS
   

 

   

Conservation Planning
Conservation planning concentrates development in smaller areas to preserve tracts of natural open space over the remainder of the site.  Several techniques exist to help retain usable open space, extend trail networks, and protect natural resources, while offering attractive and valuable building sites for development.  In rural, suburban, and urban environments, the division and use of lands should include natural boundaries as well as those that are created.  Refer to Critical Design Practices: Conservation Planning for detailed information on the components of this method.

 


 

Conservation Planning on a Regional Scale
Local jurisdictions are encouraged to identifiy and protect conservation areas within Northwest Lower Michigan.  Adjacent communities can plan conservation networks by incorporating maps of potential conservation areas as part of their master plans. Ideally these areas should interweave to form a contiguous network of open spaces.  Documentation of conservation areas should be accompanied by updated zoning and subdivision ordinances.

Areas Most Suited for Conservation Planning Techniques
~ Existing large parcel areas
~ Prime agricultural areas
~ Parcels within viewsheds
~ Ecologically sensitive lands
~ Remaining large woodland areas
~ Stream corridors and greenways

Areas Most Suited to High-Density Development
~ Areas with existing infrastructure
~ Areas where existing public infrastructure can be easily extended
~ Areas where development will not adversely impact significant natural systems
~ Areas where existing community character will not be adversely impacted

Transfer of Development Rights
Jurisdictions wishing to achieve a balance between preserving natural areas and developing housing are advised to establish a Transfer of Development Rights (TDR) program.  TDR programs redirect residential development to areas appropriate for higher densities. Refer to State of Michigan Public Act 228 of 2003 for specifics.

Density Calculations
The method communities use to calculate density can dramatically impact development patterns.  For instance, while densely arranged homes on one portion of a large parcel would have the same gross density as the same number of homes spread out evenly over the parcel, the two developments have substantially different net densities.  Hence lot size and building arrangement can result in very different residential densities.

When revising ordinances, local jurisdictions should take into consideration the implications inherent with the different methods of calculating density.  Net density produces a more visually recognizable density for the developed portion of the site, while gross density allows for more flexibility in developing sites (e.g., cluster developments, PUDs) as well as projects evaluated in the context of average density of adjacent developments (i.e., a development fitting within a density continuum).

Calculating Density

Gross density =
Total residential units / total development land area

Net density =
Total residential units / total residential land area (excludes roads, open spaces, and other uses)

Density Bonuses
Offering density bonuses is one way local jurisdictions can facilitate the creation of unique, environmentally sensitive developments.  To be effective, local jurisdictions should establish the parameters for density bonuses (i.e., under what conditions and how much) and local ordinances should include a detailed schedule indicating specific bonus housing units for various amenities (e.g., affordable housing; senior housing; parks, open space, and recreation; historic preservation; innovative stormwater management; pedestrian amenities).  Granting bonuses for the most unique and exceptional projects can encourage better development in local communities throughout Northwest Lower Michigan.