Though the building had undergone previous alterations—for example, the Church Extension and Missionary Society had "removed deteriorated parapets from the towers" in 1880—it did not undergo significant renovations until the early 1890s. That year the rose window on the front of the building was removed, "possibly because it had Christian motifs", and replaced with a large arched window, still in keeping with the Gothic style. The work was undertaken by the architectural firm of (Ernest) Schneider & (Henry) Herter, German immigrants who had worked on a number of other synagogues, including the Park East Synagogue. In 1893 they fixed "serious structural problems", the consequence of neglected maintenance. The work included "stabilizthe front steps, add[ing brick buttresses to the sides of the church for lateral support, again in a Gothic style, and replac the original basement columns with six-inch cast iron columns." A later renovation replaced the wooden stairs from the main floor to the basement with iron ones.