Minimum density establishes a minimum size (floor area ratio) for new construction. A lot of 10,000 square feet with a minimum FAR of 2 would, for example, need a structure of at least 20,000 square feet (i.e., a 2 story building that covers the full lot or a 4 story building that covers half the lot). The goal is to prevent subdividing into smaller parcels.
Maximum density limits the number of units that can be built on a lot. This limit varies by municipality but generally ranges from 1 to 4 units per acre. Some cities, such as Los Angeles, allow for more than four units per acre.
Density also affects how much you can earn. In general, the higher the density, the higher the potential return on investment. Denser neighborhoods are usually more expensive to build in. This is because there's less space available for buildings so developers tend to charge more for apartments in these neighborhoods.
The table below shows the maximum allowable density for different municipality zoning codes. These figures were provided by my local zoning attorney and they have not been verified by any outside source. They are only accurate for the specific municipalities shown and may not apply to all areas within those cities.
Category Maximum Allowable Density Units/Acres General 1-4* Commercial 5-10* Industrial 11+ Residential <1
Density does not simply relate to high-rise structures. The definition of density varies depending on the situation. Thus, in a wide region with one-acre lots for single-family detached houses, single-family dwellings on one-fourth or one-eighth acre are deemed greater density. In some city plans, anything over two stories is considered high density. While this may seem reasonable, it can have unexpected effects. For example, if all homes in an area were limited to two stories, there would be very few houses built after 1950 - most new housing would be four or more stories high.
High density means many more people per unit of land than low density. It is not always easy to define exactly what level of density is high and what is not. However, the term usually refers to developments with less than 200 units per square mile. This would include large gated communities, where each house is separated from the next by a fence or wall, or isolated houses within small residential neighborhoods.
People often dislike high-density neighborhoods because they think it must be hard to find good schools, convenient shops, and other services. But these problems can be fixed by moving to a higher density neighborhood where those things are easier to come by.
Furthermore, high density housing can be much cheaper than smaller, scattered developments. This is because you get much more housing for your money.
Simply expressed, density zoning limits property development by limiting the number of structures in a particular area in order to regulate population density. Density zoning is a method used in town planning to either increase or preserve density in a city region. It can be used as a tool for promoting community character, preserving the environment, and limiting urban sprawl.
Density zoning was first used by planners in the late 1940s to help control growth and prevent overcrowding in major cities. At that time, there were few methods available to promote sustainable communities, so planners resorted to using zoning to encourage more compact development that would be less damaging to the environment. Over the years, their knowledge has increased and so have their tools. Today, planners use a variety of techniques including density bonuses, preservation areas, and satellite cities to achieve their goals.
Comparing density zoning to other tools used in planning, planners often compare it to land use controls because both methods serve the same purpose of regulating how property is developed. However, while land use controls limit development within the grid system or around transportation corridors, density zoning focuses on densifying specific parts of the city through policies such as maximum building heights or requirements for yards between homes. Also, unlike land use controls which are usually placed at a local level, density zoning is typically put into place by state legislators or local officials and can only limit certain types of developments - not all development.
Calculation To get the minimum and maximum number of residences authorized on a property, divide the lot square footage by 43,560. (square feet in an acre). The area obtained is multiplied by the general plan density range. For example, if the result is 3 to 4 homes per acre, the property can be developed according to those guidelines.
Example: A residential subdivision has 100 acres and plans to build 3000 square feet per home. What's the lowest and highest density that can be built on the property?
Minimum Number of Homes Per Acre = 100 acres / 43,560 square feet = 2.3 residences
Maximum Number of Homes Per Acre = 100 acres / 12,960 square feet = 8.3 residences
The property can be developed with densities between these two limits.
For comparison, here are the county standards for minimum and maximum numbers of residences allowed per acre:
County Minimum Number of Homes Per Acre Maximum Number of Homes Per Acre
San Diego County 1.5 residences 3.0 residences
Los Angeles County 1 residence 4 residences
New York City 0-4 residences 5-6 residences/acre