Density Transfer Credit
Many, perhaps most, communities in New Hampshire have master plans that advocate protecting natural resources and important conservation lands, preserving open space, saving what is left of their rural character and working landscapes and preventing sprawl. Yet despite the best of intentions, most existing zoning ordinances, no matter how well crafted, will not achieve these goals. The concept of transferring development rights and the density transfer credit was devised several decades ago as a potential solution to the problem of preventing or discouraging development in places where it is physically feasible, but undesirable for one or more reasons.
Lot Size Averaging
The technique discussed here is lot size averaging, the basic concept that provided the foundation for the cluster or conservation subdivision. Lot size averaging refers to the approach of requiring the average size of all of the lots in a subdivision to be equal to or greater than a specified minimum rather than requiring that each individual lot meet the minimum size threshold. The terms “density zoning” and “area-based allocation” of dwelling units are sometimes used as well.
Feature-based density is a zoning technique where the permissible density is calculated based on a set of factors contained in the ordinance, as opposed to a uniform standard being applied to all of the land in the zoning district. Feature-based density can strengthen the ability of the planning board to ensure that the zoning ordinance and individual subdivision layouts achieve many goals of the local community.
A conservation subdivision is a residential subdivision in which a substantial amount of the site remains as permanently protected open space while the homes are located on the remaining portion of the site. Under this approach, the community works with the applicant to fit the development into the landscape in a way that maximizes the protection of important natural and cultural amenities on the site and maintains the character of the community.
Chapter 26 of the
Implementation Manual. Subdivision regulations control the pattern of development—the way land is divided up to accommodate land uses and supporting infrastructure such as roads and utilities. Subdivision regulations are meant to ensure that the division of land into smaller units results in lots or parcels that are useable and safe and reflect the physical characteristics of the site.
Transfer of Development Rights
Chapter 28 of the Implementation Manual. Transfers of development rights allow landowners in areas planned for very limited development (sending areas) to sever the development rights from their land and sell them to buyers who want to develop at higher-than-allowed densities in areas designated for growth (receiving areas).
Beginning with Habitat (BwH) Toolbox – Net Residential Density
Net residential density determines the number of units that could be placed on any given parcel during the subdivision process by subtracting the area of sensitive features from the overall acreage of the parcel. The remaining acreage is then divided by the minimum lot size in the parcel's land use zone. This calculation ultimately determines the potential number of lots that can be created. By including elements such as wetlands and certain habitat types as parcel features that are subtracted from net residential density calculations and thus remain undeveloped, a town can add an additional layer of resource protections.
Beginning with Habitat (BwH) Toolbox – Land Use Ordinance Performance Standards
The State of Maine Subdivision Law contains 20 criteria for approval of a proposed subdivision that must be considered prior to project approval. One of the main purposes of local, municipal subdivision regulations is to clarify and expand upon the criteria of the statute based on locally identified concerns and priorities. This webpage offers examples of how Maine towns have expanded upon the state required review criteria #8 (aesthetic, cultural and natural values) and added clear guidance for development project applicants.
Beginning with Habitat (BwH) Toolbox – Transfer of Development Rights and Development Transfer Fee
A Development Transfer Fee program is based of the same basic concept as TDR. The difference is that a Development Transfer Fee program is fee-based using a third party as the broker. A developer pays a transfer fee to the town. This payment enables them to buy and build an additional number of units in the designated growth area than would be allowed under current density limits. In turn, the payment is deposited into a town fund for land acquisition. Accumulated funds are then used to conserve lands in the designated rural sending areas once an opportunity becomes available.