New CNN street-level studios

In the summer of 2000, CNN initiated a search for street-level studios in New York with high visibility to show that the network was broadcasting from the world’s media capital. The network selected Meridian Design Associates Architects for the project. This article describes the process and the technical and design issues faced in the course of the project.

CNN’s new street-front studio has glass on three sides to allow a street audience to be part of productions like “American Morning with Paula Zahn.” When the studio is not in use, its street-level presence serves as marketing for the network. Photos by John W. Farrell.

The most obvious feature of a street-front studio is that it allows production that has been enclosed and “placeless” to be associated with a specific location. At the same time, it brings the production process closer to potential viewers by removing walls and opening the studio visually to the public. The effective interaction of a street audience and production is crucial to many of the shows’ formats; however, the use of the space as a TV studio is really part-time.

The majority of the time, the space serves as marketing for the network and its products. The selected site at the Time Life Building’s plaza had features that gave it an architectural advantage. The most prominent was that the space chosen for the street studio had glass on three sides. Additionally, one side was right on the Avenue of the Americas, where the hustle and bustle of a busy midtown sidewalk was visible from the studio.

Having found the location, the next challenge was to turn a commercial space that had previously housed a bank branch into a multi-studio television facility, a use inherently more demanding of the building’s infrastructure. Existing ceiling height, column spacing, available floor structural loads and available square footage posed difficulties. Creating a major stand-alone HVAC plant and managing available electrical power were also major concerns.

Another issue was security – providing safety for prominent guests while on air, as well as while entering and leaving the facility. The design team also considered lighting temperature issues to determine whether the studio should be lit with HMI luminaries to compensate for the daylight, or whether the lights should be typical tungsten fixtures, thus requiring the daylight to be filtered.

Design criteria

The space available for the project was approximately 5000 square feet at street level and 10,000 square feet one level down, in the Rockefeller Center Concourse.

The street studio for “American Morning with Paula Zahn” was the driving force for the project – thus, meeting its criteria was paramount. Not surprisingly, the mandate was given to make it as big and as high as possible, and also to make it column-free. It would have glass on three sides, but also needed to include a bullet-resistant enclosure to protect talent and guests. The second studio, a conventional “black box” studio, was to be 1000 square feet.

The new studios have a completely digital technology backbone for the broadcast operation. The studio cameras presently operating in NTSC standard are fully capable of providing HD.

The minimum height of the lighting grid above the studio floor in both spaces was to be 14 feet. The acoustical performance was to meet a minimum of NC25, and cooling capacity was to be 45W per square foot. Additionally, backup power was required to stay on the air for at least 15 minutes in case of a power outage.

Facility tour

It takes more than a studio space to house the physical requirements for a production. These additional spaces – usually referred to as “production support” – generally break down into four categories: technical, office/support, storage/maintenance and mechanical/electrical.

The technical spaces include a control room with its usual component of audio control, graphics, producer’s area, TD and equipment room; a lighting area; a video shading area; an audio mix room (mixing for musical guests); a central equipment room for transmission gear and servers; and an appropriate technical maintenance shop. In the final design, however, the requirement of a control room on site was reduced to an on-site producers’ viewing area that would mirror the functions associated with a normal producers’ station in a control room. All control room functions are handled remotely from the existing CNN facility in New York. Eight DS3 digital lines provide for up to eight camera feeds from the studios, and an additional six TV1 analog lines provide return program and plasma display feeds to the studios.

The office/support spaces needed to include talent offices, workstations for approximately 20 people, two greenrooms, and two security screening areas (one for each level). The storage/maintenance component required an entrance for scenery deliveries with large (eight-foot-wide by 12-foot-high) acoustical doors, and a separate area to stage and store the necessary materials for production in the plaza.

The electrical, mechanical and plumbing components were among the most critical. Mechanical load requirements in the studios added up to 70 tons of cooling without redundancy, another 20 tons of cooling for the space between the building’s exterior glass and the studio’s interior glass, and a balance of approximately 50 tons for the office functions and the technical spaces, for a total of 140 tons.

Production at CNN’s new facility takes place not only in the studios, but also in technical spaces like the lighting and video shading room shown above.

A key aspect of the design requirements was the “branding in place” – the primary reason for creating a street-front studio in the first place. The space between the glass walls of the studio and the building glass wall was designed by PDG to provide passersby with a news ticker/zipper sign and plasma screens with network feeds. This cavity space acts as a show window of the product and is an extension of the studio within.

Implementing the design

Due to the relatively small spaces available, especially at street level, the design team’s first order of business was to triage the uses and needs to be housed on the first floor. In the Time Life Building there are two distinct structures: the skyscraper tower and the eight-story “pavilion” where the planned studios were to be. A 1000-square-foot breezeway between the structures provided an opportunity to increase the facility’s first floor space by 20 percent. Capturing the space required extensive negotiations with building owners, CNN, the NYC Department of Buildings and the Landmarks Commission. The additional space made all the difference in creating a functional space to house a security lobby and a plaza staging area in close proximity to the studios.

In order to provide a column-free area for the money shot in the “American Morning” studio, it was decided to remove a major building column from the first floor. This is a difficult procedure in any location. In this project, it was further complicated by issues arising from the exterior detailing of the building and the impossibility of access to existing column footings – they were two cellars down among the subway tracks. The team needed to insert a structural element more than four feet deep and seven feet wide in the middle of a studio requiring critical ceiling heights, without affecting the exterior appearance of a building under the protection of the Landmarks Commission.

Figure 1. To remove a conspicuous column from the studio area, the design team added two columns in the plane of the studio’s sloping glass wall, connected by 36-inch transfer girders to keep the cavity space free of structural members. Two 52-inch girders brought the structural loads back to their original footing on the concourse level.

Ironically, the solution added two columns on the first floor in the plane of the studio’s sloping glass wall. Transfer girders spanned between the two new columns, a shorter distance than between the existing columns. The shorter span made it possible to keep the girders to 36 inches in depth and allowed the cavity space to be free of conspicuous structural members. On the concourse level, the structural loads were brought back to the column below the one removed via a pair of 52-inch-deep girders, thus transferring the load to its original footing (see Figure 1).

Studio glass wall

To create a wall that satisfied the above design parameters, i.e., visually open, bullet-resistant and acoustically adequate, was one of the most difficult tasks to realize in the project, especially since time was of the essence.

After camera-testing several options, it was decided that the most acceptable solution was a multilayer low-iron laminated glass performing to a certain Underwriter’s Laboratory (UL) security standard. The criteria for this selection were clarity and color rendition. To comply with the UL standard, the framing system also had to be part of the protective assembly. With the given conditions at the site, they were able to utilize a UL security-rated pre-fab framing system.

Glass of this type can only be manufactured in a few locations worldwide, through a lengthy and arduous process that could potentially add five months to a project schedule. So the standard avenue of first installing the support mullions and then creating templates from the installed supports was not feasible for this fast-track project. Working with a glazing consultant, their firm developed detailed computer modeling, essentially building the wall in the computer. These models were developed into shop-drawing-quality construction documents from which all elements of the wall were ordered and fabricated.

Acoustical considerations

Elimination of structure-borne sound and vibration from the subway train station located below the area of the project was the biggest acoustical challenge. Horizontal airborne noise transmission was effectively kept within design parameters by the thick glass required for security reasons. Vertically, the airborne separation in the existing building was quite good – so good, in fact, that had structure-borne noise not been such a big issue, an isolated ceiling probably would not have been required.

To abate the vibration in the structure, the team designed a four-inch reinforced concrete floor on top of a Kinetics RIM isolated floor system. The design criteria of the floor included structural design to allow for rolling loads for the security glass installation and rigging (each pane at over 3000 pounds, plus the weight of a forklift).

The need for an acoustical barrier ceiling was marginal considering that the existing structure provided an acceptable level of separation. However, to eliminate the possibility of audible rattling, precautions had to be taken to ensure that no vibration would be transferred to the lighting grid and its instruments.

Maximizing studio height

In any TV studio design project, the height of the lighting grid is critical to assure adequate light distribution. At the CNN project, this challenge was exacerbated by the column removal, which for practical purposes divided the ceiling cavity in two, and by unusually large supply ductwork to satisfy cooling demands for the studio lighting and a large solar load.

Figure 2. The ceiling system in the new studio incorporates a series of Unistrut supports anchored to building steel with spring isolators. The design provides some acoustic separation to the floor above and a place to attach the lighting grid.

The first task was to minimize the size and distribution of ductwork without creating acoustical noise issues. To this end, we split the supply and return ductwork into two zones, one for each side of the studio ceiling cavity separated by the transfer girders, eliminating ducts crossing under the transfer girders. Additionally, we eliminated the use of direct return ductwork by designing transfer ducts from the studio ceiling to the ceiling plenum, allowing the air to free flow to an opening for return at the studio wall.

The second effort was concentrated in the design of a ceiling system that would function as a plenum, provide a modest amount of acoustical separation to the floor above and provide a method to attach the lighting grid. The solution incorporated Unistrut members anchored directly to building steel by appropriately sized spring isolators and installed in a north-south direction at approximately four feet on centers. From these supports, we anchored the main members of the lighting grid pipe with the cross piping, also at four-foot centers.

This system is an adaptation of the subframe support system typically seen in much larger studio spaces, where a structural grid is provided below the finished ceiling construction to facilitate rigging and installation of lighting support systems. Installation of such subframes adds flexibility to studio spaces and also eliminates coordinating penetrations of the ceiling cavity for the lighting grid supports (see Figure 2).

The CNN project is now on the air, on time and on budget, with a street-front studio that brings the flavor of New York to viewers, and provides visibility for CNN and its products to the people of New York.

Antonio Argibay, AIA, is principal-in-charge for Meridian Design Associates.

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