Designation reaches window profile and material
Windows are the exterior element local historic designation most often governs. On a designated property, changes visible from the street can be reviewed, and that review can reach frame material, sash configuration and profile — not merely glazing performance. It can also mean original sash is expected to be repaired rather than replaced. None of that applies to an undesignated property on the same street.
Official sources
Confirm designation before specifying anything
A citywide designation procedure does not tell you your parcel's status, and neighborhood appearance is not a reliable proxy. Confirm it with the city before specifying units, and have the existing sash assessed for repair by someone whose business is not exclusively replacement.
Sources reviewed June 20, 2026. External requirements and maps can change.