2000 Avenue of the Stars, Los Angeles, USA

The relocation of ABC television has left Century City in Los Angeles ripe for redevelopment. Gene Watanabe of Gensler talks about a major new commercial and recreational space on a site rich with history.

Taking on the task of revitalising the Entertainment Center in the heart of Los Angeles' Century City means carrying the identity of the city on your shoulders.

It is not only a flagship development for the local community but also a site with a lot of history. As a result, developers have had to juggle the needs of the public and those of the private sector, as well as striking a balance between the past and the future.

The project is designed to offer a mix of commercial, office, retail, dining and public space on a site that was built 30 years ago for anchor tenant ABC Television Networks.

ABC moved out in 2000, relocating to the Disney Studio lot in Burbank and leaving large amounts of office space vacant.

The site that is left is in need of radical improvement, but offers an opportunity to create a new identity for a high-profile site, reviving it as a commercial and public centre.

2000 AVENUE OF THE STARS DESIGN

The proposed development, known as 2000 Avenue of the Stars, will offer a 12-storey office area, multiple dining facilities, shops and cultural amenities. In addition, the concrete outdoor central plaza between 2000 Avenue of the Stars and century plaza will become four acres of landscaped green space.

"Century Plaza Towers, to the east of our project, is a very prominent address," says Gene Watanabe of Gensler Architecture and Planning, a senior designer on the project.

"There was a feeling that if a new high-rise went up around them that it would diminish their importance. The two ABC buildings that we are raising and reducing blocked pedestrian flow on the corner of Avenue of the Stars and Constellation, which is now the heart of the city."

PARKING AND PEDESTRIANISATION

Recognising the prominence of the site and the desire to attract more pedestrians, a comprehensive programme of improvements in parking and pedestrian access has also been undertaken.

Add to this the emphasis on power and water conservation technologies to improve the building's environmental performance, and it is clear that Gensler has had to face numerous challenges.

Not the least of these was finding the required amount of floorspace on the site, while preserving the lines of sight and achieving a sympathetic aesthetic interaction with the surrounding structures.

"For the amount of area we were looking to develop, it was a challenge to fit in 800,000ft² of office space," says Watanabe. "We knew it had to be high-rise, but we would have had to put half of the garage below the complex out of commission and put in new foundations. We couldn't do that. We were limited by the conditions of the structure."

IMPROVED FOUNDATIONS

Using the existing footings through the garage below, the maximum height that could be sustained was found to be eight storeys, resulting in a larger floorplate of 100,000ft².

"A low structure like that would have been disastrous for the site," believes Watanabe, "so we designed new buildings with premier-sized, class-A rent floorplates, which meant we had to raise the building. We could not use the skeletons of the existing buildings, and we needed to look at a new structural system integrated into the existing garage."

One potential solution was to add columns connected to the foundation through the garage and strategically placed to support office buildings. However, these columns would have had a negative impact on the available size and usability of the garage, and parking is at a premium in LA.

"We came up with a more conducive grid," says Watanabe, "putting the new footings on columns, almost symmetrically between the existing footings, which limited how large the new footings were. So, the whole basement level is on a single, large footing. With this layout, our height was still limited, but it was up to 12 storeys."

The result is a pair of 12-storey buildings with 27,000ft² floorplates. At the second floor, and again at the eleventh and twelfth floors, the two buildings are joined by a bridge, giving the three floors a combined area of 65,000ft².

"We are finding that these bridge floors are very desirable," says Watanabe. "The building will be a striking addition, with the hole in the structure between the bridges, but it was really driven by a need to solve the problem."

A SPACE FOR THE PUBLIC

The identity of the site will also be heavily influenced by the open space at its centre.

One of the project's goals is to increase public use of Century Park, previously blocked by the wall created by the ABC buildings, which hampered access from the outside.

The location of Century City means that there is not only plenty of commercial traffic in the area but also a number of desirable residential locations in the vicinity, giving the designers an opportunity to create a major focal point for the area.

The solution to the problem of opening up access to the park from the corner of Avenue of the Stars presented itself when the team was examining alternatives for the parking facility below the building.

"We staggered the floors of the garage," says Watanabe, "tucking the parking in underground. Century City had evolved to become very dense, and the park development was part of the idea of greening the area. There was a need for underground parking when it was built, so the easiest solution then was to have a hardscaped plaza. There was almost no green space that people could enjoy."

'GREENING THE AREA'

Given the area that was available for greening, the Gensler team felt they could truly create a destination for the local community as well as commercial and tourist traffic.

"From the ground floor of the Crown Plaza Towers to the lobby of the Avenue of the Starts building there is a 30ft slope. So we created a sloping park, all on one level, which creates a graded transition between the buildings. We used that depth for planting, so it is all grass – no planters and no dirt either."

Putting earth on would have added too much weight to the underground parking structure, so the slope is largely composed of Styrofoam, with planted material on top. The result is a functionally successful design which maximises rentable office space while providing an exterior that blends with the other architectural elements.

"It will be a valuable amenity for the city," adds Watanabe. "Everyone loves the building."

At present, construction is on course, the ABC buildings have been demolished and work on the lowest foundation is under way. The tower cranes are in place and steel is still being delivered, but when the cranes move out and the site is ready for occupation by its anchor tenant in 2006, Los Angeles will have another major architectural attraction.