uilt in 1873-74, the landmarked Bouwerie Lane Theatre in New York City is a rare example of French Second Empire style. The five-story, decorative cast-iron building was first occupied by the German Exchange Bank and later converted to an off-Broadway theater in 1963.
The cast-iron framing at the head of the windows had either concave or convex corners at different floors. These curved corners were duplicated at the window frames, sash and glass. Thus, the blind stop, along with the brick moldings of the frames, the top rail of the top sash and the glass, was curved.
The type of glass varied on different floors. On the first two floors, home to several up-scale retail condominiums, we used clear and non-insulated, laminated glass because the building owner wanted the best clarity and visibility to show goods in the oversized windows. The upper floors are living spaces, where the owner wanted insulated glass for energy conservation, comfort and sound deadening, plus the appearance of turn-of-the-century glass.
For this 19th c. cast-iron building, convex or concave corners were duplicated at the window frames, sash and glass to fit within the cast-iron framing at the head of the windows. New York City, Steven Harris Architects
Unique Collaboration Uses Modern Materials to Preserve 19th Century Appearance
ollaboration between the owner, architect, and Architectural Components led to specifying the glass, a combination of “Circa 1900” glass from S.A. Bendheim for the exterior and a “Warm Edge Super Spacer” from EdgeTech and clear, laminated glass on the interior. “Circa 1900” reproduction glass is machine-rolled rather than mouth-blown. It has minor distortion and is manufactured in the same way glass was made when it was first machine-made and matches the turn-of-the-century glass that was originally used in the building.
The “Warm Edge” spacer has several advantages over traditional aluminum spacers. As the name suggests, it is warmer and does not conduct cold like an aluminum spacer because the spacer is made with synthetic foam. It is, therefore, easier to bend around tight radius corners, making it more suitable for this application. It also tends to absorb light rather than reflect light like aluminum so it is less noticeable and less objectionable. The laminated, interior glass also has many advantages. The glass is actually two pieces of glass laminated with a layer of plastic film in between. It is stronger than regular annealed-glass and if it does break it stays together in one sheet, similar to a car windshield. This is desirable for both safety and security. It also blocks 99% of harmful ultra-violet light, protecting valuables, furniture and carpets from deterioration. Lastly, the plastic interlayer helps deaden sound.
Different Joinery Methods Applied to Opposing Curved Corners
aking the wooden sash with the curved corners presented some challenges and the joinery methods varied depending on whether the corners were concave or convex. For the concave-cornered sash we joined the top rail and stiles with a bridle-mortise-and-tenon joint thus eliminating any feather edges where the curves joined the straight pieces of wood. The glass for these windows was made with curved convex corners as were the wood-glazing stops.
The convex cornered sash posed a different challenge. The glass company could not cut the glass with concave corners without lots of breakage, waste and expense. We, therefore, made the sash with square corners and square glass and applied the curved corners on top of the glass. This proved to simplify the production and costs of the woodwork and the glass.