On behalf of our AIA HRC partner, NPS Technical Services just issued an update to Preservation Brief 16 "The Use of Substitute Materials on Historic Building Exteriors"
https://www.nps.gov/orgs/1739/upload/preservation-brief-16-substitute-materials-2023-2.pdf
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Elizabeth Hallas, AIA
Anderson Hallas Architects, P.C.
Golden CO
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