The two-deck Eurasia Road Tunnel, connecting the Asian and European sides of Istanbul’s Bosphorus is 5.4km long, 3.4km of which is bored 25m below the seabed. The nerve centre of this major infrastructure project is the Operations & Maintenance Building.
The 7,150sqm site of the O & M Building is situated to the north of the D-100 highway at an altitude of 30m above sea level on the Asian Side of Istanbul. With no distinct local architecture in its immediate surroundings, the site is in a generally hostile physical environment. The design objective was to create a contemporary building with strong architectural expression and which responded to its immediate context as well as providing a pleasant office environment.
The 2-storey superstructure, positioned at the same axis as the tunnel entrance is visible from all surrounding roads and hovers above the ground level maintenance facilities. Its outer skin formed in perforated metal panels with a subtle wave-like motif creates a glowing symbol for the Eurasia Tunnel at night.
The access to the building is through a ravine, which has been cut into the hill. The natural contours of the site have been largely retained and the maintenance components of the building have been disguised behind the site contours.
At ground floor there is a large double height reception area with exhibition space, and the restaurant space opens out to a covered landscaped terrace for corporate entertaining and staff relaxation during warmer months. There is extensive landscaping around the building to minimize the effect of the surrounding roads and to help reduce pollution. The staff car parking is at the south side of the building and set in mature landscaping. Opposite the office reception is the maintenance area with its own staff entrance, and stairs to upper floors. This is a functional space with exposed concrete walls and sun pipes for day lighting. The roof is accessed via the west staircase and houses the mechanical plant concealed behind the perforated external screens.
First floor is accessed from either of the two vertical circulation cores. The maintenance offices, staff lockers/showers are located to the west of the plan. The operations offices are arranged along the two long façades. The double storey Primary Control Room, which is the nerve centre of the tunnel, is located at the eastern end of the plan. Its fully glazed façade overlooking the tunnel entrance is set at 10 degrees to minimize glare. The interior is further protected from solar gain by a large roof overhang.
The offices have been designed on a 1200mm planning grid within a structural grid system of 6m. This enables all the ceiling grids, window mullions, partitions and solar screen to be aligned and fully coordinated. All the offices have double-glazed full height aluminium windows with side opening windows for fresh air. There is a 600x600cm clip-in suspended ceiling with integrated lighting air conditioning diffusers.