A build-out analysis projects the amount and location of development that may ultimately occur in a specified area as permitted by current land development ordinances. It enables a community to test the reality of its development regulations against its vision for its future.

Summary

A build-out analysis projects the number of residential units and commercial/industrial square footage that could be built if all unprotected, buildable land within a specified area is developed in accordance with municipal zoning. Analysis can also include the impacts from permissible development on tax base, traffic, school enrollment, park needs, sewage and water facilities, natural and historic resources, farmland and rural landscapes, and overall quality of life. The results of the analysis typically are conveyed through maps and charts.

A build-out analysis allows a community to test its development regulations – to see its likely future if all the remaining buildable land in the community is developed in conformance with the municipality’s ordinances. The analysis answers the basic question: If existing land development ordinances and open space programs (or lack thereof) remain unchanged, how much land may ultimately be developed and where?

Track Record

Build-out analyses have been widely used for a long time to estimate future development potential. The tool’s effectiveness depends on whether or not the implications of the analysis are incorporated into revised land use ordinances to guide future growth.

Typical End Users

Build-out analyses are typically commissioned by local governments and occasionally by conservation organizations. The analyses are useful in that they can help guide the governing bodies of local governments and their appointed bodies (e.g., planning commissions) in considering and implementing changes to their land use ordinances. The analyses can also be useful to conservation organizations and other community groups who can use the analyses as educational tools as they advocate for more conservation-oriented policies in their municipalities.

Conservation Impact

Because a build-out analysis looks at the long-term rather than the short-term consequences of a municipality’s ordinances, it shows much more development occurring in a municipality than residents generally expect.
By presenting a clear picture of how current zoning will result in changes to a community that people generally find undesirable, a build-out analysis can be a strong catalyst for making changes to a community's land use ordinances.
Ultimately, a build-out analysis is only effective for conservation purposes if the municipality follows up with appropriate zoning changes.

What You'll Need

A build-out analysis can be conducted -- at various degrees of detail -- by laypersons, community planners and/or engineers. The land use planning analytical skills of either staff or consultants may be desirable to better ensure reliable results and credibility.
Fiscal impact expertise is desirable if fiscal impacts are to be analyzed.
Access to Geographic Information System software, and the expertise to use it, is extremely helpful, but not necessary.

Obstacles and Challenges

The build-out analysis is not necessarily attached to any point in time and therefore may not provide a clear timeframe, or sense of urgency, for implementing changes.
Sometimes there are negative reactions to build-out analyses because people believe that a full build-out will never occur
The level of development potential identified by an analysis often frightens people, who never thought their community could absorb so much growth. The traditional fix, reducing development by down-zoning (reducing the number of residential lots or non-residential square feet that can be built under zoning regulations), is fraught with political difficulty because landowners view it as a loss of property value. Zoning changes that utilize Transfer of Development Rights, Conservation by Design, and Traditional Neighborhood Design can be better approaches to managing future development pressure.

Contents of Main Description

Introduction
The Basics of a Build-Out Analysis
   Two Phases
   Geographic Information System
   Sketches of Future Street Scenes
   Scale of the Analysis
Conducting a Build-Out Analysis: A Two-Phase Approach
   Phase I
   Phase II

   Additional Impact Analysis
Constructing a Build-Out Analysis at the Intermediate or Municipal Scale
Not Just for Vacant Land

Introduction

Residents often assume that their community's zoning regulations will protect them from inappropriate development, but conventional zoning and subdivision regulations typically allow development on all buildable land. A build-out analysis allows a community to test its existing regulations, to glimpse its possible future when all land is developed to the maximum extent allowed under law. Build-out analysis is a tool that shows the consequences of not revising existing land-use regulations. The findings may lead to a municipality making changes. In any case, the analysis enables officials to make informed decisions in planning the future.

The Basics of a Build-Out Analysis

Two Phases

There are typically two phases in conducting a build-out analysis: Phase I visually depicts changes on a map, and measures additional housing units and non-residential square footage that could be built under existing zoning regulations. Phase II quantifies the impact of the additional development. A summary brings together the critical information and conclusions in an easy-to-understand way.

Geographic Information System

A computerized geographic information system (GIS) is helpful. GIS allows data to be combined, managed, manipulated and analyzed. A GIS can be used to determine the number of additional dwelling units and non-residential square feet that could be built on developable land in the study area under the existing zoning regulations. A GIS can provide a user-friendly model for electronically layering maps to allow users to easily visualize where development in a community might occur. Depending on the software, this information can then be shared via the internet without the requirement that end-users purchase GIS software.

Sketches of Future Street Scenes

If a community wants to take the analysis one step further, a graphic artist could use the Phase I results to prepare sketches of possible future street scenes. (The computer software Community Viz could be applied to this purpose.)

Scale of the Analysis

Before starting, you will need to determine the scale at which you will conduct the analysis. Although the more detailed the analysis, the greater level of accuracy and information you will have, increasing detail will also increase the amount of resources you will need to invest in creating the analysis.

At the micro-scale, each parcel is analyzed to account for zoning requirements and physical constraints.

At an intermediate scale, parcels are analyzed using the same constraint parameters across the study area. For example, all parcels within the study area could be grouped and evaluated as a whole by zoning districts. Although this approach is useful if time and data availability do not allow for a more detailed analysis, whether or not this scale will give sufficient accuracy will depend on the intended use. This level of analysis will not allow a locality to know where exactly development can occur.

More detailed information about scale can be found in the paper “Build-Out Analysis in GIS as a Planning Tool With a Demonstration for Roanoke County, Virginia” by Mary A. Zirkle.

Conducting a Build-Out Analysis: A Two-Phase Approach

Phase I

First, construct a base map of your community. The base map should show the basics, such as:

the perimeter of the community
north arrow
scale of the map
existing roads
surface water (lakes, rivers, streams)
zoning districts

The base map should:

delineate land that cannot be developed due to public ownership, deed restrictions and utility easements.
delineate land that cannot be developed due to environmental constraints such as wetlands, floodplains, or steep slopes (but do not include steep slopes which could be graded into developable land). Some parcels may be partially developable, due to restrictions such as utility easements.
delineate land that has already been developed with existing structures and lot lines.
delineate land that will be developed in the near future (indicated by building proposals that are expected to be approved shortly, approved building proposals, and land under construction). This new development should be added to the new development estimated from the build-out analysis to determine the total number of new housing units and non-residential square footage. The total number of new housing units and non-residential square footage is what is used to determine future impacts.

After the base map is created, the next step is creating overlay maps that show land that may be developed further. Then calculate what development may occur by applying the zoning regulations to the total acres developable. This will yield total buildable dwelling units and/or total buildable non-residential square feet by zoning district.

For land zoned residential, apply road standards and minimum lot size and frontage requirements as if the land was developed to the maximum extent allowable. Subtract 10% from the developable residential zoning districts to account for streets and infrastructure, with the remainder equaling the net total acres developable by zoning district.
For land zoned commercial apply the largest amount of floor space allowed under the zoning regulations
For a mixed-use district, it is advised to assume the greatest percentage of non-residential uses and of higher density residential uses permitted per development.

Communities that have a high percentage of undeveloped or underdeveloped land may want to do staggered overlays showing the possible progression of growth. For instance, the first might show growth along major roads and on large parcels. The next overlay might show growth on the next most desirable parcels. The last could show growth on the least desirable parcels.

Phase II

Phase II is a quantitative analysis of the impact of the changes detailed in Phase I. Numbers to calculate might include changes in:

the amount of impermeable surface, which impacts water quality.
acreage farmed
population/number of school-age children
housing units / housing density
traffic
tax revenues
demands on schools, water supply, sewage, electrical production, police force, etc.

Additional Impact Analysis

Additional analysis should be based on the priorities and capacity of the municipality and is not a requirement of a build-out analysis. In the impact analysis, a community determines what is important to them. Additional factors that might be considered are:

impacts on views from allowable building heights
impacts on noise levels
impacts from hours of operation
parking needs and impacts from spillover parking onto streets or other parking lots

Constructing a Build-Out Analysis at the Intermediate or Municipal Scale

The following is a detailed discussion of how a build-out analysis is typically constructed. Note that most build-out analyses use Geographic Information Systems (GIS). GIS is used to determine the number of additional dwelling units and non-residential square feet that could be built on developable land in the study area under the existing zoning regulations. The number of additional dwelling units can be converted to population, based on current or projected household sizes per municipality, and the number of additional non-residential square feet can be converted to employees, based on employment generation standards from The Fiscal Impact Handbook by Robert W. Burchell and David Listokin.

First, Geographic Information System (GIS) data sets are gathered which include parcel data, land use, environmental constraints such as floodplains and wetlands, and zoning districts. The total acreage of developable land is calculated by zoning district. Undeveloped land (vacant, wooded, and agricultural) and land deemed appropriate for redevelopment are considered “developable”. Environmentally constrained lands (floodplain, wetlands, steep slopes, and any other areas where development is regulated) are then subtracted from the total developable acres. An additional 10% is subtracted from the resulting amount in residential zoning districts to account for streets and infrastructure, with the remainder equaling the net total acres developable by zoning district.

The particular zoning regulations per district are applied to the net total acres developable to yield total buildable dwelling units and total buildable non-residential square feet. Many assumptions in interpreting the zoning regulations will need to be made. For example, in a mixed use district, it is advised to assume the greatest percentage of non-residential uses and of higher density residential uses permitted per development.

To calculate the achievable Floor Area Ratio (FAR), which is often different than the permitted FAR, use the formula:

FAR = Impervious Coverage Ratio

1 + 400SF (square feet)

# of Stories Parking ratio

Impervious Coverage Ratio: The maximum percentage of the site that may be covered by impervious surfaces (buildings, parking lots, driveways, etc) stated in the zoning ordinance.

Number of Stories: Manufacturing and warehousing type uses are always assumed to be built as one story. Likewise, retail is assumed to consume one floor only. Generally, only offices are deemed likely to be built on more than one story, for which the maximum number of stories permitted, stated in the ordinance, should be used.

400 SF: A standard amount of impervious coverage per parking space, aisle, and associated driveway space.

Parking ratio: The ratio stated in the zoning ordinance per gross square feet of building space. For example, a common parking ratio requirement for office use is 1 space per 200 SF of building space. The parking ratio in this case would be 200, meaning 200 SF per 1 parking space.

Developable land that will be developed in the near future (indicated by building proposals that were expected to be approved shortly, approved building proposals, and land under construction) should be subtracted from the net total acres developable prior to the application of the zoning regulations. Data on dwelling units and non-residential square feet for these areas can then be added to the buildable dwelling units and buildable square feet found after the zoning regulations are applied.

Employment generation can be based on standards from The Fiscal Impact Handbook by Robert W. Burchell and David Listokin. The following standards can be applied to the district’s most prominent uses:

Shopping Centers: 1 employee per 500 SF GLA (gross leasable area)

Offices: 1 employee per 250 SG NLA (net leasable area)

Industrial Plants: 1 employee per 300 SF NLA

Warehouses: 1 employee per 750 SF GLA

Not Just for Vacant Land

Build-out analysis is not just for communities with vacant land. Any community with property that has not yet been developed to the full extent allowable under law might benefit from a build-out analysis.

Conservation Tools

Build-Out Analysis

Experts

Featured Library Items

Acknowledgements

Disclaimer

Copyright