Some compliance requirements may call for evaluation of historic standing structures or engineering features. Adverse effect on those structures/features that are determined eligible for inclusion on the National Register of Historic Places can be mitigated through documentation according to the Historic American Building Survey/Historic American Engineering Record (HABS/HAER). The goal of HABS/HAER documentation is to preserve a thorough record (written, photographic and line drawings) of the structure.
Each project is carried out in three stages:
- Archival research and records review
- Field inspection and documentation
- Assessment of the architectural and historic significance of the resources examined
Other services associated with historic structures that PTA offers, include: