Reglaze or Replace?

Originally known as The Master Building, 310 Riverside Drive in Manhattan's Upper West Side is a 28-story tower completed in 1929 as an apartment hotel and museum. With its Art Deco design rendered primarily in brick masonry and monumental steel windows above the ground floor entrances and marquees, this designated-Landmark is a unique example of the high-rise typology that came to define the NYC skyline during the first half of the 20th century.

It is a familiar question to preservationists – how do you balance the historical value of character-defining existing single-glaze windows with their historically poor energy performance? This presentation examines the steel window and storefront restoration, rehabilitation and replacement options devised for this project. It outlines the decision-making process that led to the retention of the original non-thermally broken steel window frames and the installation of replacement vacuum insulated glazing (VIG) within them, and the process of pursing custom-made VIG panels to replicate the textured blue glass at the side lites.

VIG is not a new glazing technology, but until very recently it required importing from Asia or Europe at a premium in cost and long lead times. Few projects in the US have been fully realized using VIG, and data on its performance in existing frames is practically non-existent. Now that VIG is becoming more readably available in the US, the technology seems poised to bridge the long-standing gap between preservation and the kind of high energy performance usually reserved for new buildings.

For this case study, samples of VIG were installed in existing frames prior to the work implementation to monitor heat flow through the proposed replacement VIG in comparison with the original single-pane glass and existing non thermally-broken steel frames. Data collected from this case study indicated that the VIG panes decrease the U-value of the system by about 73% (almost 4 times improvement). The presentation will present a critical look at VIG and its application to existing buildings as a viable alternative to wholesale window replacement.