İstanbul Arts Facility Features Steel ‘Box' inside a Preserved Shell

A VENERABLE APARTMENT building in İstanbul, Turkey, has been converted into a new cultural center that will provide a permanent home for the Borusan İstanbul Philharmonic Orchestra as well as exhibition space for various artists. The new Borusan Music and Art House was designed by GAD Architecture, which has offices in İstanbul and New York City, to "preserve the architectural legacy of Istanbul" and to accommodate t lie "cultural and artistic renaissance presently occurring throughout the city,” explains Gokhan Avcioglu, the founder and principal of GAD, in a written response to questions from Civil Engineering.

The arts facility was constructed inside a 19th-century apartment building that essentially had been gutted by its various owners, leaving only the decorative stone facade and the interior perimeter steel reinforcement in (dace. Within that masonry shell.GAD Architecture designed a lightweight steel diagonal grid (diagrid) framework that was welded to the existing steel work, structurally reinforcing the facade and transferring seismic loads to a new composite floor system that was constructed within the diagrid. The resulting "contemporary box within the core...seems to defy gravity as it responds to, and is framed by historical masonry shell,"explains Avcioglu. The "symbiosis of the two contrasting construction methods and materials activates a playful tension between the just and the present," he adds.

GAD designed both the architectural and the structural system for the Borusan Music and Art House, which opened in January and provides rehearsal at concert space for the Borusan Istanbul Philharmonic Orchestra exhibition space for artists. The Istanbul-based engineering firm Büro Statik Mühendislik assisted (GAD in various ways, including determining the dimensions of certain diagrid elements, designing an additional foundation system, and calculating the forces the structure would need to accommodate notes Mclis Eyüboğlıı, an architect on the- GAD design team.

Borusan Holding, an Istanbul-based steel, energy and telecommunications conglomerate, was GADs client for the 19 USD million project.

Located in the historic Beyoğlu district, in northern Istanbul, the building that now houses the arts facility features a large main entrance on İstiklal Caddesi, the street with the highest elevation in the neighborhood and one that I us been converted to mostly pedestrian traffic; a secondary entrance is located along the intersecting street. It has six stories above grade plus a rooftop terrace level and a basement level. The original floors, which were demolished by the previous owner, were of wood. 'Pic new diagrid system consists of  low steel pipe sections 6 in. in diameter that arc filled with concrete, a material chat helps to increase the system's fire resistance and to alleviate acoustic problems, notes Avcioglu. The diagrid frame is rectangular in plan and measures 12.6 m in the east-west direction and 9 m in the north-south direction. Arranged to form a series of X-shapcd supports over two floors, the exposed diagrid elements appear as either a V or an inverted V within each space.

A scries of columns encasing steel I-beam sections with tlangc widths of 200 mm frame tlte staircases that link the lloors; the columns are located outside of tlte diaghd framework in hallways along the perimeter of the new steel structure. A series of I beams with web heights of 290 mm and transverse I beams with web heights ranging from 100 to 300 mm support the new flooring system, which consists of sheet metal decking on which the trapezoidal channels are covered by a concrete slab.

The building is located in an area prone to severe seismic activity. Its composite flooring system was therefore designed to accommodate the seismic loads specified under Turkish earthquake regulations for buildings in the cinema and theater category, says Avcioglu. "The floor system also helps to provide "more stable and thus mote comfortable conditions’ while also presenting deflections and vibrations, Avcioglu notes.

With a footprint of 230 m’ and a gross floor area of 1,900 m\ the structure provides exhibition spaces at the ground level and the second level, which is considered the first floor. The two-story concert hall on the second and third floors includes a balcony 1.8 m in width; tlx lull can seat up to 100 persons. The fourth their features rehearsal moms while the fifth floor serves as a multipurpose space. The sixth floor houses a café and a bar. and open-air spaces there offer views of the Bosporus; a small seventh level serves as a terrace. A new elevator system was installed reconnect all of the doors except the terrace, which tan be accessed only by a new staircase.

The buildings original perimeter foundation system was not altered during the renovations, but a new concrete raft foundation I m in depth was constructed to support the new interior construction, Avcioglu says.

Artwork is integrated intothc building "as if they were construct«! at tlx same time," note Avcioglu. For example, the installation Untitled, by the American artist Leo Villareal, features light-emitting diode tubes that arc used to illuminate the V-shaped diagonal supports To help restore the buildings original appearance, mullions were installed on the single-pane window systems located on the facade along ; İstiklal Caddesi, Avcioglu adds.

Other key members of the project s design team in GAD architects Scott Baltimore, Baris Ucar, and " Ozan Ertug, as well as Büro Statik Muhendislik structural engineers Ceyhun Güdül, Odun İlkay Etguncs. Fatih Ycsilsclvi, and Send Söylemez.—ROBERT L REID