Table of Contents
Cluster subdivisions are a land development tool used by communities to protect open space or environmentally-sensitive lands, including hazard-prone lands. Clustering development simply means grouping or directing new development to relatively less sensitive areas within a subdivision, away from more sensitive areas like open space, steep slopes, or floodplains. Cluster subdivisions (also sometimes known as “conservation subdivisions”) generally do not increase the overall density of a development but rather allow dwellings to be grouped (or “clustered”) on smaller lots away from sensitive areas such as rivers or defined natural hazard areas. The key benefit to a developer is smaller lot sizes than otherwise permitted by the subdivision regulations in exchange for the conservation of sensitive lands. A developer also may benefit from local incentives that encourage the use of clustering, such as density bonuses, or state incentives, such as water rights.
Cluster subdivisions are implemented through a community’s subdivision regulations. Subdivision regulations are a community’s opportunity to address new development in terms of location and density of lots, protection of environmentally-sensitive areas, and to meet other community goals. Communities that are interested in establishing cluster subdivision provisions can do so via a new ordinance or by amending their existing subdivision ordinance. Cluster subdivisions can be mandatory or used as an optional incentive in combination with other tools such as density bonuses and/or transfer of development rights (TDRs), both of which are addressed separately in this guide.
Longmont authorizes cluster lot subdivisions in its Land Development Code. Cluster lot subdivisions must be located in certain zoning districts and be of a minimum overall site area. While not explicitly designed to avoid hazard-prone lands, they are intended to create more compact residential developments to preserve and maintain open areas and natural lands (which often can include areas prone to hazards). They must provide common open space that meets specified requirements. Cluster lots are permitted in the R-1 and R-2 zoning districts, where minimum lot sizes are normally 5,500 and 5,000 square feet, respectively, for a single-family detached dwelling, but may be reduced in a cluster development to 3,000 square feet. The maximum development density is still limited to the R-1 and R-2 standards. Other minimum dimensional standards are also reduced for cluster subdivision lots in these districts, such as lot widths and setbacks. Approval of cluster lot subdivisions must follow the procedures for standard subdivisions in Longmont (Code of Ordinances, 2015).
The primary benefit to adopting cluster subdivision regulations is the protection of environmentally sensitive areas and, in the case of hazard mitigation, protection of areas that pose risk to development. The development community also benefits from cluster subdivisions through paired incentives such as density bonuses. Other advantages include:
- There are synergies with other community goals and assets. Clustering development allows communities to protect development from hazard areas, while also conserving other sensitive areas such as wildlife habitat and migration corridors.
- The footprint of new development is reduced. When development is clustered, the needs for grading, paving roads, and laying infrastructure are diminished.
- Long-term maintenance costs are reduced. Because cluster development has a smaller footprint, this can equate to lower costs for maintaining roads, infrastructure, and other public or private amenities.
- Cluster subdivisions can be tailored to any Colorado community. Depending on political climate and demand, cluster subdivision can be mandatory or optional, and can be implemented through rigorous or more flexible standards. Tying cluster subdivision to other incentives such as TDRs or density bonuses is also optional.
- Property values may rise. Clustering has the potential to increase property values, since individual lots will enjoy access to an increased amount of open space.
- Varied housing stock. Cluster subdivisions often mean smaller lots, which can result in smaller dwellings, meeting diverse community housing needs.
- Wildfire risk reduction in the wildland-urban interface (WUI). Clustering lots away from the wildland-urban interface can reduce the wildfire risk to property and life.
Developing a cluster subdivision ordinance is relatively straightforward because there are many successful models in use around Colorado; however, there are some costs and challenges associated with the process.
- Less developable land. Without other incentives, developers may be forced to build smaller homes on smaller lots, making it difficult to maximize profit.
- Higher open space maintenance costs. Depending on the particular subdivision, the burden of maintaining the protected or open areas could become the responsibility of the developer or a subsequent metropolitan district or homeowners association. If dedicated to the local government, maintaining those areas becomes the responsibility of that jurisdiction.
Administrative Capacity
Experienced planners with city or county attorney to write regulations and normal capability to administer the standards once adopted
Mapping
Not required, but sample cluster subdivision layout drawings help illustrate the desired result through the cluster subdivision process
Regulatory Requirements
Subdivision ordinance required to effectively administer cluster subdivisions
Maintenance
Minimal
Adoption Required
Yes
Statutory Reference
The adoption of subdivision regulations is authorized for municipalities and required for counties through detailed enabling legislation (C.R.S. § 30-28-133 for counties and § 31-23-214 for municipalities). Local governments may adopt cluster subdivision provisions as part of this general enabling authority
Associated Costs
Staff time and ordinance development or amendment costs
Examples of the Tool
Archuleta County Subdivision Regulations
City of Aurora Small Lot Development Standards
DOLA Model Codes Cluster Subdivision Regulations
City of Durango Cluster Development
Larimer County Rural Land Use Process
City of Longmont Cluster Lot Subdivisions
Town of Pagosa Springs Conservation Subdivisions
Routt County Land Preservation Subdivision
Summit County Rural Land Use Subdivision Process
For More Information
EPA’s Essential Smart Growth Fixes for Rural Planning, Zoning, and Development Codes