"In a recent study, Avrami et al. (2018), found 86% of the local historic preservation ordinances sampled across the United States are nearly 100% derivative of the standards for significance and historical integrity found in the federal National Register (NR) of Historic Places guidelines. In my own work, I’ve also found this to be the case; the remaining 15% or so are basically paraphrasing the NR standards with very few exceptions. In addition, I’ve found that more than 95% of local preservation ordinances either directly reference the federal Secretary of the Interior’s Standards, copy the standards verbatim, or paraphrase them in some way. Lastly, a random sample of historic preservation ordinances shows that nearly all of these ordinances do exactly the same thing, which are to:
If these look familiar, they should, because Richard Roddewig prepared a guideline for “how to create an historic preservation ordinance” for the American Planning Association back in 1983 with exactly this content. There’s never been an update to this document, and it’s still referenced in practice, to this day, when new preservation ordinances are being proposed."