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|Federal Highway Administration > Publications > Public Roads > Vol. 76 · No. 5 > Postwar Houses: A Transportation Timebomb?|
Publication Number: FHWA-HRT-13-003
Postwar Houses: A Transportation Timebomb?
by Emily Pettis and Amy Squitieri
NCHRP has developed a model for evaluating the mid-century residences that soon might trigger a huge need for Section 106 compliance by Federal-aid or federally permitted highway projects.
If you look at the built environment along major transportation corridors, you might notice entire subdivisions and neighborhoods full of similar houses built between the mid-1940s and 1970s. Many of these houses reflect the architectural styles and forms popular at the time, including minimal traditional, colonial revival, ranch, contemporary, and split-level models. Vast numbers of these houses were built in response to a significant housing shortage and population boom in the years following World War II.
Across the country, large urban areas such as greater Minneapolis, MN, smaller cities like Lincoln, NE, and formerly rural areas experienced significant growth and development during the post-World War II period. Although some geographic variation exists, noticeably in building materials and exterior ornamentation, many of these houses are nearly identical in style and form.
Fast-forward to the present day. The large number of these houses poses a potentially huge challenge for planners of transportation projects. Why? Many such houses are now, or soon will be, more than 50 years old and, therefore, are subject to evaluation for eligibility in the National Register of Historic Places. Pursuant to Section 106 of the National Historic Preservation Act of 1966, agencies seeking Federal dollars or permits must take into account the potential effects of their projects on properties eligible for listing in the National Register. As a result, transportation project planners increasingly must consider postwar residences as part of a project’s compliance with Section 106.
With so many houses from that era, how do Federal agencies decide which ones represent the best examples of their respective styles and contexts -- that is, those that are likely to be eligible for listing in the National Register? A research team working for the Transportation Research Board’s (TRB) National Cooperative Highway Research Program (NCHRP) took an important step toward providing answers in a 2012 report, A Model for Identifying and Evaluating the Historic Significance of Post-World War II Housing (NCHRP Report 723). The report establishes a national historic context, or narrative history, of residential properties of the postwar era and outlines methodologies for streamlining survey and evaluation of those properties for eligibility for listing in the National Register.
Relevance to Transportation Agencies
By 1945, the national housing backlog that began during the Great Depression and continued during the war had left approximately 3.6 million families searching for homes of their own. To address this deficit, new housing starts reached a total of 1,023,000 in 1946. (For comparison, new housing starts numbered 326,000 in 1945 and just 142,000 in 1944.) A variety of factors contributed to the housing boom, including the postwar economic upswing, returning servicemen and women, the GI Bill, the baby boom, the Federal Housing Act of 1949, and the growth of the middle class. As postwar residential construction continued, the number of new houses built between 1946 and 1975 grew to more than 40 million.
Some of these postwar residences have already reached the National Register’s usual eligibility threshold of 50 years old, and many more will in the near future. State departments of transportation (DOTs) -- on behalf of the Federal Highway Administration (FHWA) -- State Historic Preservation Offices (SHPOs), metropolitan planning organizations, and cultural resources professionals now are faced with the challenge of evaluating the significance and integrity of these resources efficiently and consistently.
Currently, to begin Section 106 compliance, many DOTs use traditional survey methods to document each resource that meets or is approaching the 50-year mark, regardless of appearance. They then apply existing National Register guidance to evaluate resources for historic significance. The sheer volume of postwar houses that might need to be surveyed and subsequently evaluated results in significantly increased costs for transportation projects. In addition, evaluations of individual postwar residences and neighborhoods are often complicated by the fact that few housing resources from the recent past have been studied thus far, so comparative information is often unavailable.
In order to comply with Section 106 for transportation projects, State DOTs, on behalf of FHWA, have to consider steps to avoid, minimize, or mitigate (in that order) adverse project impacts on properties that are listed on or determined eligible for listing on the National Register through the survey and evaluation process. If a project is expected to affect a listed or eligible property, Section 106 outlines specific steps the Federal agency needs to follow. The agency must take into consideration the type of resource and effect, and the outcome of consultation during the public involvement process. For example, the DOT might revise the project alignment to avoid an adverse impact on an eligible resource. If the alignment cannot be changed, the DOT might take steps to mitigate project activities, which could include shielding the resource with landscaping, documenting the resource with archival photos, or conducting activities to educate the public on the value of the resource. Or a DOT might relocate a resource, such as moving a historic building or bridge to a new location outside the immediate project area, or install a historic marker in place of the removed resource.
The TRB Response
A few DOTs and SHPOs have begun to address the challenge of surveying and evaluating the ever-increasing number of postwar residences by developing statewide historic contexts -- historical narratives describing postwar development and associated resources -- and tailoring National Register eligibility requirements. But, taking the solution a step further, NCHRP initiated a project to create a broader model that will provide an opportunity to improve consistency among the States and across agencies. In 2012, a research team selected by NCHRP and guided by a panel of experts completed work on a national historic context and methodologies for surveying and evaluating single-family residences from the postwar era.
The research team, consisting of cultural resources professionals, formulated and tested the historic context and methodologies presented in NCHRP Report 723. The project was overseen by NCHRP staff and a research panel consisting of 12 representatives from State DOTs, SHPOs, FHWA, and the National Park Service. The final report includes three components -- a national historic context, a survey methodology, and an evaluation methodology -- that together provide a standard framework that transportation and cultural resources professionals can use to evaluate postwar housing.
National Historic Context
The first component of the framework is the national historic context, which is a narrative history of postwar residential development between 1945 and 1976 in the United States. The historic context, as written in NCHRP Report 723, highlights the social, economic, governmental, and political influences on the development of housing resources nationally. It also describes the overall development of housing during the postwar period and covers national trends that influenced the development of postwar residences.
The context’s provision of a succinct background and history of nationwide trends and influences on postwar housing can benefit transportation and cultural resources professionals by minimizing the research an agency would need to perform for a specific transportation project. Instead, the agency can focus its time and resources zeroing in on the local historic context and its relationship to the national trends, such as development of urban expressways and suburbanization.
Project historians conducted extensive research to develop the national context. They reviewed primary and secondary sources, as well as previously prepared historic contexts, National Register nominations, and results from regional and statewide studies of postwar housing. The historic context addresses the following topics:
Popular architectural forms and styles of the period also are discussed in detail, including their evolution and character-defining features. Photographs of the housing popular during this period illustrate the definitions. Few architectural style guides cover the postwar period in detail, and this document could prove beneficial in providing consistent terminology for use nationwide.
“The challenges of identifying and evaluating American architecture during the mid-twentieth century cannot be understated,” says Sandy Lawrence, history team leader with the Georgia Department of Transportation and chair of the NCHRP project panel. “By establishing a national context, a framework for establishing State and local contexts, and a protocol for identification and evaluation based upon that context, the study team has given historic preservation professionals invaluable tools upon which to base their studies of mid-century residential resources, no matter where these studies are initiated.”
In addition to the national historic context, the researchers prepared a model outline to guide the development of a location-specific historic context during transportation project planning. The model for the local historic context follows the organization of the national model and is intended to serve as a guide for research efforts and context development likely to be needed for Section 106 compliance on a transportation project.
The second component of the framework is a methodology to assist agencies with surveying postwar single-family residences. Traditional approaches followed by many State DOTs and their consultants require a field survey of every building that is 50, or in some cases 40, years old. Field surveys entail photographing and documenting the characteristics of each building, such as approximate age, architectural details, construction materials, and any alterations.
This methodology can result in repetitive documentation of numerous similar or even identical houses. In the case of a project that might affect a large postwar subdivision, this approach could result in a significant expenditure of time, resources, and budget to document hundreds or even thousands of similar resources.
To reduce this effort, NCHRP Report 723 presents a survey methodology that provides a streamlined and consistent approach to identifying and evaluating both groupings of houses and individual resources. In developing the methodology, the NCHRP project team reviewed a variety of previously completed postwar compliance and community survey reports to identify successful and efficient approaches.
Specifically, the methodology presented in the study recommends surveying concentrations of similar postwar residences as a single group or potential district rather than documenting individual houses. This approach works best in a neighborhood or subdivision where postwar houses display similar forms, massing (footprint of the original house), and materials. Each resource does not need to be documented individually, which, in turn, reduces the associated project costs and time commitment.
A recent transportation compliance project in the Minneapolis suburb of St. Louis Park, MN, might have benefitted from such a streamlined approach, according to Heather Goodson, a project manager with Mead & Hunt, the contractor that was responsible for overseeing the project’s field survey. The suburb saw exponential residential development between 1945 and 1950, with hundreds of very similar minimal traditional and transitional ranch houses constructed in the community. Following the established practices in the State, Goodson’s team of architectural historians performing the survey and evaluations required under Section 106 documented approximately 100 individual residences located within the area of potential effect, creating many nearly identical survey records, rather than a single record for the overall neighborhood.
“By employing [NCHRP Report 723’s] streamlined methodology and documenting the neighborhood as a collection rather than individual resources,” Goodson says, “[we] would have significantly reduced the amount of time spent completing fieldwork and compiling supplemental survey documentation. This would have resulted in a smaller overall effort that could have been completed in less time.”
Instead of documenting numerous individual houses that all meet the age requirement, historians using this streamlined survey methodology could complete just one field survey form documenting the neighborhood as a collection, and highlighting specific houses that retain character-defining features. Rather than shooting photos of each individual house in the neighborhood, the historians could photograph the streetscape and a couple of representative houses and document the similarities in form, style, age, construction materials, and other architectural elements -- saving time and money.
The survey methodology also provides guidance for the selective survey of individual resources, which should be used when the grouping approach is not applicable. This approach focuses on surveying only those individual residences that retain historic integrity and a minimum number of character-defining features. Although historians review all properties within the survey area, they document only those properties that have the greatest potential to be recommended as eligible for listing in the National Register. NCHRP Report 723 provides specific guidance on the popular architectural forms and styles of the postwar period, including illustrated examples of properties that meet -- and do not meet -- the selective survey criteria.
Testing the Survey Methodology
Project team members tested this selective approach in several geographic areas to confirm its streamlining benefits. Arlington County, VA, was one test area. The county’s proximity to Washington, DC, led to rapid residential development in the early postwar years, and the area includes large concentrations of similar colonial revival and minimal traditional residences. By using the selective survey approach, the project team was able to reduce significantly the number of properties that required documentation.
“Using the survey methodology enabled us to eliminate 70 to 80 percent of the resources that we would typically document in a reconnaissance-level survey,” says Patti Kuhn, an architectural historian with Louis Berger Group, Inc., who led the Arlington survey effort. “By streamlining the process, we were able to focus our efforts on documenting only those resources that may meet National Register criteria. We also were able to reduce the number of hours spent in the field and preparing survey documentation.”
During the course of the project, officials with the Virginia Department of Transportation (VDOT) had the opportunity to review the test survey results. “I found the methodology employed in the Arlington demonstration areas to be an efficient use of time and effort,” says Helen Ross, VDOT district preservation manager. “To go through a neighborhood looking for resources that still possess some integrity and then evaluate that resource for eligibility translates nicely for transportation projects. We’ve been operating by looking at the neighborhood as a whole and then identifying the architectural styles and evaluating the entire property for eligibility for the National Register. But basing our findings on, for example, integrity of materials and design, and acknowledging the historic context from which the house was conceived, is an expedient way of assessing significance for the huge number of post-World War II dwellings in Virginia.”
The third and final component of the framework is the evaluation methodology, which provides guidance for evaluating resources to determine whether they might be eligible for the National Register. The researchers developed guidance for consistently applying the National Register’s criteria to postwar residences, considering both the significance of individual houses and the historic districts. In developing the methodology, project team historians reviewed relevant National Register bulletins, nominations, and multiple property documents, as well as a variety of previously completed postwar compliance and community survey reports.
In addition to guiding application of the National Register criteria, the methodology also includes detailed and illustrated examples of common alterations that could compromise the integrity of individual residences and districts, resulting in a “not eligible” recommendation. For example, replacement front doors and garage doors that are the same size as the original may be deemed compatible and would not necessarily result in diminished integrity. However, alterations to a house’s original roofline, such as the addition of dormer windows or a second story, are considered incompatible and typically result in diminished historic integrity.
Using this methodology can help transportation project planners achieve more consistent and streamlined evaluations of postwar neighborhoods, subdivisions, and individual residences across geographic areas. In addition, its use can result in more predictable Section 106 reviews, thereby enabling agencies to deliver projects faster.
The NCHRP report illustrates the evaluation methodology guidance with case studies of postwar residences and historic districts that have been listed in or determined to be eligible for the National Register. Along with the guidance, the case studies can assist professionals in applying the criteria for the National Register to postwar residences. The examples also provide a national perspective by showing National Register-eligible resources from multiple geographic areas.
A Practical Approach
Ultimately, NCHRP Report 723 presents a practical approach to diffusing the timebomb of postwar housing and streamlining the process of determining potential eligibility of these residences for listing in the National Register. The DOT then can move forward with developing the transportation project once any historic properties are identified. Any efforts to avoid, minimize, or mitigate potential adverse impacts on properties deemed eligible remain a necessary component of the Section 106 process, and FHWA and the involved State DOT are responsible for determining next steps and consulting with the property owners and other relevant stakeholders.
The historic context outline and two methodological tools (for survey and evaluation) developed by the research team provide first-of-their-kind national guidance for assessing postwar housing. Having representatives from varied geographic perspectives on both the NCHRP project team and research panel overseeing it ensured that the approach would consider regional differences as well as be applicable at the national level.
According to MaryAnn Naber, preservation officer at FHWA and a member of the NCHRP research panel, the practical approach outlined in the report will be useful to FHWA, State DOTs, SHPOs, and cultural resources professionals everywhere. “Ultimately, the use of the national context and streamlined survey methodology is expected to lower project costs and help expedite schedules, assisting DOTs and FHWA with fulfilling their missions to efficiently deliver transpor-tation projects.”
Another potential benefit is that a consistent, credible approach to surveying and evaluating postwar residences could go a long way toward changing the perception among practitioners and the public that postwar houses are not important for understanding the Nation’s heritage, while at the same time conveying that not every individual house is historic.
“Although some postwar residential buildings may not be individually eligible for National Register listing, the postwar period nevertheless saw a major residential building boom that transformed community planning and development, architectural standards, and social history,” says Jeffrey Durbin, Section 106 compliance officer with the National Park Service. “Postwar residences tell a unique story of these important housing trends, both in the distinctive architectural styles and forms that developed following the technologies and societal preferences after World War II and in the large new subdivisions built to meet the explosive demand.”
Emily Pettis is a senior historian with Mead & Hunt and served as co-principal investigator for the NCHRP Report 723 project. She led survey teams in documenting postwar resources nationwide. She currently is leading a citywide residential survey of Detroit, MI, which includes large areas of postwar development.
Amy Squitieri served as co-principal investigator for the NCHRP Report 723 project. She is vice president of Mead & Hunt. She has helped many State transportation agencies identify and prioritize postwar resources, including bridges and residences.
For more information, see NCHRP Report 723, A Model for Identifying and Evaluating the Historic Significance of Post-World War II Housing, which is available for download at www.trb.org/Main/Blurbs/167790.aspx. Or contact Emily Pettis at firstname.lastname@example.org.
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