Historic panel conditions slate repair at 190 Nassau, allows synthetic slate on adjacent roof

The Princeton Historic Preservation Commission on May 26 approved a modified preservation plan for two adjoining properties on Nassau Street, directing that the original slate roof on 190 Nassau be repaired in kind while allowing a DaVinci synthetic slate substitute on the neighboring building as a condition of approval.

Sarah Quinlan, Princeton’s historic preservation officer, told commissioners the block contains buildings from multiple periods and noted that 190 Nassau retains historic slate while the neighboring building has asphalt. Quinlan’s staff report advised commissioners to evaluate the proposal against the Secretary of the Interior’s Standards and the municipal historic‑preservation ordinance, which generally favor repair of historic materials and require substitute materials to match in shape and size when originals are unavailable.

Attorney Andrew Schrager, representing the property owner, said the existing slate and roof valleys show extensive deterioration and leaks that justify replacement in some areas; he described the proposal as a way to preserve use of the buildings while addressing ongoing water intrusion. Contractor Dominic Varello, who has installed synthetic slate products in the region, said manufacturers now offer longer warranties and peppered color patterns to create a more natural appearance.

Commissioners questioned product longevity and color variation, discussed whether partial repair would suffice, and asked whether the applicant could provide more documentation about the extent of deterioration. Commissioner Charlotte (functional label: Committee member) moved to require repair of the original slate on 190 Nassau and to allow replacement of the asphalt roof on the adjoining building with DaVinci synthetic slate as a modification to the preservation plan. The motion was seconded and passed on a roll‑call vote; the commission memorialized the resolution with conditions requiring the applicant to update the preservation plan to reflect the in‑kind repair requirement and other staff conditions.

The approval is conditioned on documentation and modification of the application to show that repair options were considered and that substitute materials match required shape and size where slate is unavailable. The commission noted it could request further evidence, including contractor testimony or additional photos, if questions about repairability remain. The applicant may modify and resubmit portions of the preservation plan as required by the resolution.

The commission’s action was procedural and focused on material standards; members repeatedly said economic considerations can inform—but do not substitute for—documentary evidence about whether historic materials can reasonably be repaired.