The Landmarks Preservation Commission would rather have a building owner repair existing, original windows by filling with wood fillers and epoxies etc., than replace them. There are, however, newly manufactured windows that the Commission usually will approve. See our upcoming blog entry on the analysis of window options for 168 Clinton St. where we discuss the current appropriateness of the bias towards this approach and the decision making process for 168 Clinton St.

Below is a reprint from The City of New York Landmarks Preservation Commission Guidelines and Materials Checklists for Performing Work on Landmarked Buildings:

Ordinary Maintenance (No permit required)
The following are examples of the types of work that are considered ordinary maintenance and do not generally require a permit from the Commission:
• weather stripping;
• caulking;
• puttying;
• replacing broken glass;
• repairing suspension systems (cords, pulleys, etc.);
• repairing or replacing window hardware; repairing window components by partial replacement,
scraping, filling, or sanding;
• painting window sash or frames the same color;
• installing interior storm windows or panels;
• installing interior security gates or grilles; and
• installing regulation child guards.

Approval Required for Work
The following are examples of the types of work that require a permit from the Commission:
• painting window sash or frames a different color;
• installing new window sash or frames;
• installing exterior storm windows and exterior storm window frames;
• installing or removing exterior shutters;
• installing window awnings;
• repairing or altering window enframements;
• installing or removing exterior security window grilles or bars;
• changing the shape or design of window openings;
• blocking in existing windows or creating new ones;
• restoring original or architecturally appropriate window openings; and
• replacing extensive amounts of original window materials or consolidating windows with epoxies or other plastics.