Saturday, November 21, 2009

Numeric vs. Values-Based Evaluation of Heritage Properties

Picture this if you will. A world-famous architect has been paid an enormous sum of money to create a brand new structure at a highly visible intersection in downtown London, Ontario. When completed, the new structure is considered an eyesore that disrupts what was once a lovely streetscape. While an excellent example of a particular style and design, the structure is reviled by all who see it, and becomes a landmark for misspent money and poor planning. Unfortunately for everyone involved, according to London’s newly revised Built Heritage Resource Evaluation document this much hated building would be considered a top priority for historical designation. Why? Because this building could potentially receive a priority 1 ranking for 7 of the City’s 14 possible evaluation criteria, which according to the “Priority Level Recommendation Rules” would make it one of “London’s most important heritage structures.”[i]

This is an extreme illustration of only one of the problems associated with a numerically-based evaluation system for heritage resources. Let me first say that when London revised their system, they used several other municipalities’ systems as guides, so they are by no means alone in dealing with the potential problems caused by a numerically based system.

A common critique of the numerically-based system is that it only values what is “old and beautiful”.[ii] Other shortfalls of a numerically-based system include the following.

1. Architecture, particularly high-style architecture, becomes over-represented due to the inflated scores it receives.

2. Representative examples of vernacular and working-class structures remain under-represented because they receive too few marks in the Architectural Significance category (which in London’s case is 42% of the marks, 50% if you include Landmark, which is often the case with high-style residential architecture).

3. The emphasis on architecture makes the designation of cultural landscapes more difficult.

4. The use of a formula in determining significance (or degree of significance) obfuscates the fact that evaluation is a very subjective practice. Individuals will undoubtedly interpret terms differently if they are not defined, such as determining rank based on associations that are “very strong”, “strong” or “moderate”. Until somebody defines these terms and makes the definitions widely available, there is no way to ensure consistency in evaluations.

A possible solution to the issues raised in numerically-based evaluation systems is the increasingly common practice of values-centred significance. In this system, a resources is considered to be either significant or not. It can be significant for any number of reasons, all of which are included in the London evaluation system. The difference is that in the values-based significance model a resource merits designation if it fulfills even a single criterion (although most fulfill several).

Benefits of values-centred evaluation include the following.
1. It is easier to designate buildings that are not of high architectural significance.

2. It accepts and legitimizes a whole range of values apart from the “old and beautiful”. This also recognized that values can change over time, and that different people can value the same resource for different reasons.

3. It lends itself to the designation of cultural landscapes which may not have architectural features to evaluate.

4. While still subjective, it makes the process far more transparent because interested parties will know exactly why a resource was designated rather than have to explain the scores given by multiple committee members and the reasoning behind them.

5. Values-based evaluation “can yield much more detailed, sensitive appraisals of significance” because they are not tied down to pre-determined questions about what is significant.[iii]

Values-centered evaluation is widely practiced, and has been gaining increasing popularity for a number of years. The federal government, as well as most, if not all provincial governments subscribe to this system, as do many municipalities. Perhaps it is time the City of London did as well.

[i] London Cultural Heritage Resources: Building and Property Evaluation Sheets, 10.
[ii] Randal Mason, “Theoretical and Practical Arguments for Values-Centered Preservation” CRM; The Journal of Heritage Stewardship Vol.3, No.2 (Summer 2006), 35.
[iii] Randall Mason, “Fixing Historic Preservation: A Constructive Critique of ‘Significance’” Places, Vol.16, No.1, 2003, 68.

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