The aging Chicago Historic Resources Survey, or CHRS, is Chicago’s benchmark document for determining what the city considers historic. However, without contemporary updates, it fails to protect modern (and postmodern) architectural heritage and leaves vernacular structures regularly at risk for demolition.

Chicago embarked on its very first survey of historic buildings in 1983 with the objective to identify new landmarks. The CHRS was a complex undertaking, combining research in archives and libraries with detailed field assessments and photography. A half-million properties were surveyed, with the work completed in 1994.

Dividing up the city into Chicago’s system of 77 community areas and 50 wards, the survey work began with teams driving through each ward and color coding each property according to three criteria adopted by the CHRS: age, degree of physical integrity, and level of possible significance.

Buildings given a red rating were determined to be significant on a national scale, the “best of the best” of historic resources. Orange properties possessed similar features but were significant locally. Yellow properties were identified as relatively significant and within a greater concentration of similar buildings. Yellow-green buildings were identified as being within a concentration of significant buildings but reflected alterations. Green buildings were identified in previous state surveys, and purple buildings reflected significant alterations. Lastly, the survey team included a category for buildings constructed after 1940 that were considered too new to be properly evaluated, blue, except in cases where significance was already established.

Data forms and photographs were produced for each property in the second phase of fieldwork, as well as follow-up research including zoning and building permits. In total, 22 people worked on the CHRS over the course of the 13-year, $1.2 million-dollar project. A summary of the survey was published in 1996 and widely distributed at Chicago public libraries, but it only represented a selection of significant buildings.

After the orange-rated 1927 Chicago Mercantile Exchange Building was demolished without oversight, the City Council approved a proposal sponsored by Mayor Richard M. Daley that would grant a measure of protection to significant buildings. Adopted in 2003, the Demolition Delay Ordinance requires a 90-day hold on the issuance of a demolition permit for a building rated red or orange in the CHRS.

The CHRS online database is widely used to determine if a building is an “eligible” historic resource. Unfortunately, neither the online database nor the published summary fully represents the estimated 500,000 buildings that were included in the field assessment. Each only includes a selection of buildings that fell under subjective eligibility criteria, with the city GIS website only representing data on red- and orange-rated buildings.

Demolition delay has become the most significant function of the CHRS, yet it was never the intention of the survey to have the data determine whether a building is demolished without a review of significance. The survey organizers felt strongly that the survey would have to be periodically updated to ensure accuracy.

The “modern” cutoff date of 1940 was selected to provide a 50-year waiting period for eligible buildings based on the anticipated 1990 completion of the fieldwork. This determination mirrored the National Register of Historic Places requirement for a building to be at least 50 years old before its eligibility may be determined. It was felt that this choice would allow surveyors to be more objective, but there has been no public attempt to survey or evaluate midcentury modern resources. As only red- and orange-rated resources are subject to the Demolition Delay ordinance, most modern and postmodern buildings could be at risk.



Buildings that were new at the time of the survey are rapidly aging to eligibility and could be threatened with demolition without a municipal matrix to protect them. Postmodern architecture is only represented in the CHRS if it is included but not contributing to a local landmark district. This leaves most of Chicago’s postmodern architectural heritage absent, including all of the work of Stanley Tigerman and Harry Weese, as well as the James R. Thompson Center.

In the survey, there are inconsistencies across neighborhoods and styles of architecture as well as works by individual architects. For example, a similar grouping of structures may be identified with a “warm” color rating in one neighborhood and have no information and no color rating in another. Vernacular buildings—the structures that make up Chicago’s neighborhoods—are disproportionately represented throughout the survey. Choices that include what modern buildings to include and how surveyors color rated them lack a degree of impartiality, as not enough time had passed between their construction and evaluation to make a fair, non-aesthetic judgment.

Furthermore, while the original survey team included historic resources that are individually listed on the National Register, are National Historic Landmarks, and contribute to historic districts, the surveyors did not evaluate buildings that were already designated as City of Chicago Landmarks. While Chicago Landmarks are well known, the omission of established landmarks within the CHRS data makes the overall results less comprehensive. This also renders it difficult for researchers to review Chicago Landmark and CHRS data concurrently.

While work has been done to informally update the data of the CHRS, no update or reinterpretation of the CHRS data or attempt to resurvey the portions of Chicago that are missing from the data would have the same effect as a comprehensive effort by a city-managed municipal survey. The Chicago Landmarks Ordinance states that the Commission on Chicago Landmarks must “encourage the continuation of surveys and studies of Chicago’s historical and architectural resources and the maintenance and updating of a register of areas, districts, places, buildings, structures, works of art, and other objects which may be worthy of landmark designations.”

History is not static, and old buildings are continually taking on the mantle of significance, some by aging into it, some due to changing mindsets, and others by losing enough of their stylistic comrades to become rare when once they were common. The data that we rely on to determine what buildings are saved and what buildings are demolished in Chicago is at best 24 years old, and at worst 35. An updated CHRS, one that evaluates modern and postmodern architectural heritage and takes a fresh look at vernacular architecture, is the only way that Chicago can continue to protect its architectural heritage.

Many thanks to Susannah Ribstein, Tim Whittman, and Charlie Pipal for assisting with this article.

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