Form Based Codes (FBC) Case Study

Lowell, MA
Aerial sketch of downtown Lawrence.

Since the adoption of the Master Plan in 2003, the City Council, the Lowell Planning Board, and the Division of Planning and Development have completed a comprehensive planning process to revise and improve the Lowell Zoning Ordinance. In December 2003, the first phase of this process was completed when the City adopted a new Zoning Ordinance, which provided an updated structure and addressed many inconsistencies and conflicts in the prior version. At that time, the City also adopted a number of new procedures and regulations aimed at promoting and protecting neighborhood character in accordance with the Master Plan.

In December 2004, the second phase was completed. It included revisions to the Zoning Map to guide development over the next twenty years toward appropriate locations across a variety of distinct neighborhoods, as designated in the Master Plan. As shown in Figure 1, the new map rezones the entire city using a new set of zoning districts that are designed to reflect the existing character of the city's neighborhoods on a block-by-block basis and regulate new development to respect and complement the existing neighborhood character.

More recently, in April 2006, the City adopted a comprehensive revision of the Zoning Ordinance including provisions of Form-Based Codes (FBCs). The primary purpose of using FBCs in the Ordinance was to discourage inappropriate infill development and tear-downs of existing historic structures in established residential neighborhoods. It was also undertaken to allow new development to reflect existing neighborhood character and implement the goals of the Master Plan including expanding housing opportunities and stimulating economic development in the downtown and outlying commercial districts.

Regulating Plan

Consistent with the goals and objectives of the City's Master Plan, the City adopted a new transect-based zoning map with single and mixed-use districts established along with new use and dimensional controls, including the use of FBCs for detailing particular design elements like setbacks, height, open space and off-street parking areas. The City is divided into seven (7) types of residential, six (6) types of commercial and mixed-use, and five (5) types of office, industrial and special purpose districts. Adhering to an adaptation of Duany's "Urban Transect", three types of residential neighborhoods are delineated: suburban, traditional neighborhoods, and urban communities.

Lowell's Transect-Based Neighborhood Zoning Map.
Lowell's Transect-Based Neighborhood Zoning Map

The transect-based Zoning Map divides the city into new districts based upon the existing character of the city's neighborhoods. The map corresponds with specific FBCs for setbacks, height, open space and off-street parking regulations that vary across a transect of neighborhood districts. Neighborhood types are defined to reflect a distinct neighborhood character. Overall, there are two (2) "Suburban" residential districts, four (4) "Traditional Neighborhood" districts, two (2) "Urban Neighborhood" districts, as well as six (6) commercial districts and five (5) office or industrial districts located across an urban transect.

Supplementing the Zoning Map, the Table of Uses (PDF Link) regulates the type of buildings or land uses that can be constructed within each neighborhood district along the transect while the Table of Dimensional Regulations (PDF Link) controls how these uses and buildings relate to the public realm or streetscape through a form-based set of dimensional controls.

Frontyard Setback.
Frontyard Setback

Building Form Standards

IIn developing FBCs, the city sought to establish mandated design standards in the Table of Dimensional Regulations for a host of front facade treatments such as building setback, height, landscaping, parking and garage placement.

Based on a comprehensive analysis across the main neighborhood types, these specific frontyard dimensional standards were calibrated to the neighborhood context. In conjunction with the Table of Dimensional Controls, Figure 2 illustrates how the code defines the frontyard setbacks for a variety of building elements (such as porches, stoops, projections and garages). FBCs are also used to regulate site landscaping and open space as well as a variety of other dimensional controls such as lot width, building height, and parking lot design.

Using the Table of Dimensional Regulations to define urban or building form standards, the ordinance allows multiple frontyard setbacks, particularly within the traditional or older neighborhood districts. Realizing the limitations of standardizing the dimensional requirements across distinct neighborhoods within the same zone, the ordinance also provides exemptions for building height and frontyard setback based on the height or setback of abutting buildings. This provides better continuity along the public realm and maintains the overall character of a street or block within a larger neighborhood zoning district.

Similarly, the FBCs also include innovative provisions to permit new buildings or additions to buildings to be "offset" within the sideyard setbacks. In this case, new buildings or additions are still required to meet a minimum sideyard setback, but are permitted to place the new building or additions much closer to one side of the property - more in character with the other existing buildings within the neighborhood. Additionally, the Table of Dimensional Regulations has specific limitations on the setback for front-facing garage doors and frontyard landscaping is also required in order to maintain or enhance the existing neighborhood streetscape.

In summary, although specific illustrative "Building Form Standards" have not been developed for the Lowell ordinance, the transect-based requirements listed in the Table of Dimensional Regulations produces a similar design outcome. By expanding the definition of frontyard setbacks across five main building elements (minimum and maximum setbacks, projections, porches and garages), providing a range of sideyard setbacks, a minimum usable open space provision as well as two regulations governing the height of a building, the Lowell Ordinance represents a partial application of FBCs. Moreover, the detailed text, tables, images and illustrations included in the Table of Dimensional Regulations, Definitions, and Off-Street Parking requirements all help explain the intention of the specific code requirements and strengthen the effectiveness of the ordinance. As the city continues to more fully implement FBCs, a comprehensive streetscape regulating plan and associated standards for public space or street improvements, as well as detailed architectural design standards, will strengthen the effectiveness of the ordinance.

Administrative Review

The administrative review varies within the overall approach adopted by Lowell, in a manner similar to many other communities. The use of by-right, by-right with Site Plan Review, or special permit requirements changes based on project scale or proposed use. These approaches are primarily listed within the Table of Uses and Dimensional Regulations. The form-based requirements vary somewhat within special permit applications as the evaluation criteria must be consistent with the Master Plan, neighborhood character, environmental impacts, traffic circulation, and other criteria. In the absence of FBCs for public improvements or architectural design standards, the special permit process facilitates a balanced design review process. The Zoning Ordinance also requires Site Plan Review (SPR), administered by the Planning Board, for commercial projects over 10,000 SF in gross floor area, expanded parking lots, multi-family residential developments or large single family projects approved under MGL 41, Section 81P (Approval Not Required lots). As part of the submission requirements, all projects are required to prepare detailed architectural plans that show the ground floor plan and architectural elevations of all proposed buildings sufficient to establish views of the structure from the public way.

Public Space / Street Standards

With respect to the semi-public space within the frontyard setback area, the Table of Dimensional Regulations mandates the setback requirements for the frontyard setbacks, height, projections, porches and garages. Within the urban and traditional neighborhood districts, the regulations require a "maximum" frontyard building setback in order to establish a consistent streetscape. Moreover, the maximum height, frontyard setback, or projection requirements can also be reduced in order to match existing abutting buildings on the same street. For multi-family structures, the front door or main entrance to the dwelling units is also required to be located on the front building wall facing the public street.

Landscaping for Parking Lot.
Landscaping for Parking Lot

Similarly, for public off-street parking areas, the zoning requires that there be at least a 3-5 foot setback of all parking spaces from the building wall and that parking is not permitted within the usable open space areas required for all residential districts. In order to clarify the design of off-street parking areas, the Ordinance also includes a series of graphical illustrations to clarify how these landscaping requirements should be met for the frontyard setback as well as for landscaping parking lots. Currently, the Subdivision Control Regulations are being reviewed and updated to more accurately reflect the goals of the Master Plan and will most likely include illustrative definitions for street type layouts, traffic calming measures, low impact stormwater management, lighting and detailed architectural standards and guidelines.


Typical to FBCs, the Lowell Ordinance frequently uses graphical illustrations in order to clarify the definitions applicable to the design elements such as building height, lot width and other dimensional requirements. Figure 4 illustrates how building height is calculated based on the ridge height of the building and the finished grades of the property. Further, the inclusion of a maximum number of stories as well as providing a definition of "story" prevents property owners from compressing the floor-to-ceiling height in order to maximize the total floor area of the structure. This design approach often negatively impacts the exterior character of the building's fenestration, sense of entry and overall consistency with traditional building design. In contrast to conventional dimensional controls that often define the overall height of buildings from the average existing grade around the building to the highest point of the building, a FBC approach considers calculation for the maximum number of stories permitted in the ordinance in order to provide better protection of the existing neighborhood character and the relationship of the building design to the public right-of-way.

Building height drawing.
Building Height

Lowell's use of form-based illustrations within definitions included throughout the ordinance helps to provide clear direction to city officials and property owners. The ordinance includes helpful design-related definitions for usable open space, frontyard setbacks, defining stories, lot width and other dimensional requirements.

Architectural Design Standards

Although not yet included in Lowell's Zoning Ordinance, there are some general provisions for architectural standards under the Site Plan Review and the Special Permit criteria. Similar to many communities throughout Massachusetts, the Lowell Ordinance contains a Site Plan Review process for the review of larger commercial, industrial or residential projects. The application requirements include references for "Architectural Plan" which includes the ground floor plan and architectural elevations of all proposed buildings. The plans must be sufficient to "establish views of the structure or structures from the public way" . However, the ordinance does not include more specific language to determine whether architectural elements such as roof design, massing, building materials or detailing of the windows or doors are within the Planning Board's review of the project. Similarly, the Ordinance also includes another general reference to architectural design standards in the Special Permit for a "Planned Residential Development" where perspective sketches, elevations and/or renderings showing proposed streetscapes and building designs are required.

In contrast, the Special Permit for the "Conversion of Existing Buildings" includes strict architectural standards for exterior alterations to historic buildings or neighborhood landmarks. In fact, the Special Permit cannot be issued for a project unless "the exterior design of the structure is not substantially altered". Finally, a "Neighborhood Character Special Permit" is required for adding two or more residential dwelling units on a property where only one dwelling unit previously existed. The permit requires adherence to the evaluation criteria listed for all Special Permits. Although lacking detailed architectural design standards, this criterion does include specific references to how the proposed project protects or enhances the existing neighborhood character. For example, the evaluation criteria consider whether the project reflects the "density, urban design, setbacks, height, and landscape elements of the surrounding buildings" and whether it is "consistent with the character, materials and scale of buildings in the vicinity". Further, it evaluates whether the project "minimizes the visual intrusion from visible parking, storage and other outdoor services areas viewed from public ways and abutting residences." In an effort to clarify these design issues, the Planning Office also uses a "Residential Development Guidelines for Neighborhoods" booklet to frame the design review process.

Understanding the shortcomings of the existing design standards and subjectivity of the review process, the next phase of implementation includes the formation of formal design review standards and the establishment of a Design Review Board. Detailed architectural standards are expected for front façade treatments and fenestration within selected neighborhood business districts and the Hamilton Canal District. The design standards will likely also include illustrations for projects like porches, decks and stoops as well as other design elements like garages, parking and landscaping. Similarly, the location and number of structures on each lot will be addressed and illustrative diagrams will demonstrate the effect of the "lot frontage per dwelling unit requirement" already listed in the Table of Dimensional Regulations.

Challenges and Status

Some of the challenges identified in adopting form-based codes in Lowell included the difficulty of maintaining consistency with State Zoning Act (MGL 40A) in respect to adding mandatory architectural standards outside a special permit process or a 40R Smart Growth District. Another issue of using FBCs was funding the cost of conducting charettes and other public workshops needed to develop the codes. Although initially confusing to the development community, the design and review process has become easier to understand and implement. Local architects have played a central role in developing contextual plans and assisting the Division of Planning and Department with preliminary design review. However, given the absence of formal architectural standards for building design such as massing, materials, and fenestration a design review process is being considered along with a set of detailed form-based design standards. Accordingly to City Planners, although abutters and neighborhood groups still oppose projects, residents appear less fearful of seeing poorly-designed infill projects approved under the ordinance. As such, it appears that many groups traditionally opposed to all development on density grounds increasingly recognize that the city had a design problem rather than a density problem.

As a next stage of implementation, the City intends to complete an update of their subdivision rules and regulations to include detailed streetscape improvement standards within the different transect zones. The codes will encourage traffic calming measures to keep traffic slow on subdivision streets. Additionally, the code will encourage stormwater management practices that are appropriate for the level of urban or suburban development. A series of Neighborhood Business Districts will also be established with FBCs and the Hamilton Canal Entitlement Process is underway to select a developer and develop specific FBCs for redevelopment of the district.

Further Information

For more information on Lowell's Form-Based Code, please contact Matthew Coggins at the Lowell Division of Planning and Department at or 978.446.7200. In addition, you can view the Ordinance and other Form-Based Initiatives here.