Symphony House Condominiums

Location:

440 South Broad Street, Philadelphia, PA
 

Owner:

Symphony House Associates, Dranoff Properties, Philadelphia, PA
 

Architect:

Bower, Lewis Thrower (BLT) Architects, Philadelphia, PA
 

Engineer:

The Harmon Group, King of Prussia, PA (Structural)
 

Contractor:

L.F. Driscoll Co., Bala Cynwyd, PA
Intech Construction, Philadelphia, PA
 

Project Scope

Sq. Footage:

507,000
 

Levels/Floors:

32-story condominium tower with retail, parking and 365-seat live theater
 

Architectural Precast Elements:

• 805 lightweight precast panels on the exterior.
• Precast installation completed in five months
 
 
 
 
 
 
 
Symphony House Condominiums
Symphony House Condominiums
Symphony House Condominiums
Symphony House Condominiums
Symphony House Condominiums
Symphony House Condominiums
Symphony House Condominiums
 
 
 
 
 
 
 
 
 
 
 
 
 

This 507,000 square foot, 32-story tower with ground level retail and adjacent 25,000 square foot theater is constructed in the “wedding cake” stepped-silhouette tradition of the greatest urban buildings of the 20th century. Terraces and overhanging balcony treatments enhance the traditional feel of the building, adding the period luxury this traditional style permits. Inside are 163 luxury condominiums ideally situated to allow residents to take advantage of Philadelphia’s vibrant culture and arts district.

The first eight levels of the building contain parking, theater and retail and are clad in conventional precast panels. The upper 24 residential floors are clad in the lightweight carbon fiber reinforced precast concrete panels fabricated to a thickness of seven inches to allow deep aesthetically pleasing reveals, recessed planes and window recesses adding a pleasing balance of light and shadow. This capacity for three dimensional articulation gives it a significant advantage over other systems.

Because of the unique, restrictive urban site in a historic neighborhood, the design team agreed on using the new precast technology that would capture the needed aesthetics while saving weight to allow more open interiors, reduced superstructure and foundation requirements and an overall reduced carbon footprint.

Backed with insulating EPS foam, the architectural panels weigh only 30 pounds per square foot, less than half the weight of conventional precast concrete panels. The panels contain significantly less concrete due to their structural design, and because concrete cover is not needed to protect the carbon fiber reinforcement from corrosion.

The shipping and erection of the panels entailed significantly less embodied energy than conventional precast, helping reduce the project’s carbon footprint. Reduced embodied energy was also achieved in the fabrication of the panels because less cement was used.

The insulating foam also contributes to the thermal performance of the building envelope.

Meeting Specific Design Requirements
The design team had three non-negotiable requirements: aesthetics; color depth and consistency; and water-tightness.

Aesthetically it’s a very “retro” building. It bucks the trend toward sleek glass walls and undulating curves. It’s a contrarian that seeks to please the new urban demographic it was designed for, letting them live in the grandeur and romance of the 1920s with the most modern comforts and conveniences available.

The design team had specific color and texture requirements. They wanted a textured red finish, complemented by limestone colored sections and trim and dark brown accents. This was accomplished by a combination of pigments and stains.

The precast system performs as a face-sealed curtainwall to reduce moisture risk, a preferable design over rainscreen brick veneer or liability-burdened EIFS. The insulation embedded in the architectural panels mitigates the chance of condensation-related mold or mildew in the cavity wall.

Extensive testing ensured against microcracking or water absorption. Pre-glazed mock up panels were tested extensively for water penetration, air infiltration and deflection. The panels were tested to Category 5-force wind loads using an aircraft engine.

Benefits of Lightweight Precast Panels
The restrictive building site necessitated a tower crane to lift the 805 exterior panels into place. The lightweight precast panels, which use 50 percent less concrete than conventional panels, were easily accommodated by the crane—even at the more distant corners of the building.

Panels were attached directly to the slab, a significant engineering change that contributed to larger, more economical panel sizes with fewer joints. Slab attachment allowed panel placement where it was aesthetically appropriate, so no compromises had to be made in the design. Until carbon fiber reinforcing, precast concrete had to be connected to the structure at the column because there wasn’t enough support in a concrete slab to take the load. The lightweight panels permitted connections in the post-tensioned slab without panel rotation.

In addition, the lightweight panels reduced loads on the floor slab and the rest of the reinforced concrete structure. This reduced the number of size and columns, permitting more open floor plans and lowering superstructure and foundation costs. Less weight overall means the building will perform better in seismic events than would a heavier, conventional precast-clad building.

Success All Around
Developer Carl Dranoff of Dranoff Properties is noted for his track record of renovating historic properties and converting them into luxury residences. For this highly prominent high rise condo tower, just steps from the Kimmel Center for the Performing Arts, he wanted to create a classic design that was distinctive, yet would also blend with the character and tradition of nearby structures along Philadelphia's Avenue of the Arts. The success of Symphony House proves that precast concrete is a viable player on Philadelphia's Avenue of the Arts and anywhere owners, developers, builders and architects want flexibility of design, speed of construction and cost effective quality. “Precast construction offered us more design options at no greater construction costs,” noted Dranoff. “We stayed on schedule completing erection in just five months.” “Plus precast panels gave us exactly the look and feel we wanted for the structure and for the prominent urban location. We really couldn't have made a better choice,” notes Dranoff.

 
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