Poppenhusen Institute

A designated New York City Landmark since 1970 and listed on the National Register of Historic Places, the Poppenhusen Institute is a rare surviving civic building from 1868, originally constructed by German immigrant and philanthropist Conrad Poppenhusen. This restoration project focused on building-wide envelope work, including historically sensitive window replacement, in-kind masonry repair, and accessibility upgrades.

The scope included the replacement of all 97 windows with custom, weight-and-chain, double-hung wood windows that replicate the historic profiles, brickmolds, and finish colors. The monumental Grand Hall windows—each approximately 20 feet tall—are among the most striking features, now faithfully reconstructed to match the originals. Deteriorated cast stone sills and arched hoods were replaced in-kind, while cracked surrounds were repaired using Lithomex lime-based patching mortar, selected for its compatibility with the Institute’s unique 19th-century cast stone construction. Repair materials and methods were informed by an extensive series of material laboratory tests, supported in part by a grant from the New York Landmarks Conservancy, ensuring an approach rooted in preservation best practices and long-term durability.

Decorative wood elements at the dormers were rebuilt in-kind, and flashing was introduced at all new openings to improve long-term durability. At the south façade, a rear wood door was replaced with a historically accurate barrier-free entry, complete with an automatic opener and signage. Original masonry openings infilled with brick were restored, including wood surround and transom repair. On the interior, all wood window trim was patched, painted, and replastered to align with the Institute’s character.

Paint finishes from Fine Paints of Europe were specified to match the building’s original historic palette. Similarly, repointing and patching mortar colors were carefully selected to blend with the existing cast stone and joint work. All finishes and materials were subject to thorough review to meet preservation standards, supporting the project's goal of maintaining the architectural integrity of the Poppenhusen Institute.