Geneva Airport, Aile Est

The Aile Est (East wing) project represents an important improvement for Geneva Airport in terms of passenger comfort and flexibility of its operation.

It will enable Geneva Airport to strengthen its position in the Central Europe region, as well as acting as a gateway to the city of Geneva. The new world-class passenger facilities will replace existing facilities that were built for temporary use in the mid-1970s. The Aile Est will serve Non-Schengen flights, in particular, medium and long haul carriers. Six out of seven of the gates will be contact-stands designed to accommodate code C/D/E and F aircrafts. Four of the contact-stands will be “MARS” stands designed to serve two aircraft at once.

The Aile Est consists of a "Processor" with immigration and emigration passport control booths and Non-Schengen departure and arrival gates with the capacity to accommodate airline lounges at mezzanine level.

The jetty, which is 520m in length, is based on a collaborative approach with consultants forming the RBI-T consortium being based in primarily three countries: UK, France and Switzerland. It is designed to meet the objective of delivering an energy positive building, in regards to energy consumption. In order to reach this objective, the building will rely on a holistic sustainable strategy consisting of the following elements: 7,000 m² of photovoltaic panels on the roof, 110 geothermal piles for heating and cooling, high-performance glazed facades with solar protection guaranteeing a low dependency on artificial lighting, detailed analysis of thermal performance to eliminate cold-bridges, energy-efficient chilled ceilings throughout, LED lighting strategy with responsive control systems and low water consumption using methods such as rainwater harvesting.

The RBI-T Aile Est design was selected from an OJEU competition launched in 2010. The winning design was based on ten key principles:

• The desire for a strong image
• The quality of the passenger space with an emphasis on natural daylight
• Maximum transparency
• A model for lasting development
• Evolutionary building with long-term adaptability

• Flexibility in term of passenger flows
• An airfield free of constraints
• Unification of the landside and airfield campus
• Modular construction
• An efficient construction methodology based on prefabrication

A single linear horizontal volume as seen from the airside is a key aspect of the Aile Est’s distinctive image. By placing vertical circulation for departing and arriving passengers within the main volume in the form of “circulation valves”, the airside facade is continuous and interrupted only by the air-bridges to the aircraft. The lack of circulation towers on the airside elevation also facilities excellent views of the airfield for departing and arriving passengers.

The extruded rhomboid of the Aile Est is 19m deep by 10m high and floats 6m above apron level. It extends 520m between its east and west gable elevations.

The building’s arrangement derives from a number of constraints. Due to the limited distance from the runway and the prescribed dimensions of the taxiways and the aircraft stands, the building has the unusual feature of being lifted off the ground to allow for the head-of-stand road to lie directly under the building.

The building is set out on a long-span 20 x 20m module with four modules allowed for each stand. The external steel portal at 20m spacing and internal long-span trusses are visible and carefully articulated to express the load paths.

The space available to bring services and escape stairs to ground and also to connect with the basement service room is restricted to a 5 metre strip to the landside of the service road. This manifests in the distinct legible volumes of the stair and service cores every 80m which clearly delineate between these separate service components and served space of the extruded volume.

To maximise daylight to a neighbouring building to the landside and to eliminate the risk of glare from the fully glazed façade facing the airfield the building leans at 26 degrees to the vertical. The passenger flow takes advantage of the resulting geometry such that arriving passengers walk off the air bridges directly into a vertical “valve” and then join an arrival corridor that runs longitudinally along the airside façade. Departing passengers enjoy fantastic close-up views of the aircraft on stand, the airfield and runway with a back-drop of the Jura Mountains to the north.

The material palette has been selected for its durability, low maintenance and to provide a calm, consistent background to passenger movement. Transparent, fire-rated glazed partitions are generally used to separate passenger flows thus maximising natural daylight and assisting way-finding. The floor finish is granite and back-painted glass panels are applied to the limited number of vertical surfaces that are not transparent. Powder-coated chilled ceilings and select back-painted glazing panels are colour-coded by gate to further assist passengers’ orientation along the pier.

The construction of the Aile Est consisted of four tranches of work which formed four separate contracts. The pier was constructed immediately behind six existing remote stands, that would become contact stands once the pier was built, and immediately in front of the existing baggage handling building that served the entire airfield. The uninterrupted operation of these were vital for the airport operation. This placed an onerous constraint on the access to the airfield and the phasing of the works.

Enabling Works – November 2012 to July 2013

Comprised the relocation of an apron-level hydrocarbon separator, the installation of geothermal piles to a depth of 300 metres as well as the infrastructure required to harvest and recycle waste and surface water.

“Route Douanière” ("Customs road") - August 2013 to May 2015

This infrastructure project consisted of a 7m deep, 300m long concrete basement section for the eastern half of the site. The key aspect of the design was placing underground the “Route Douaniere” (Customs Road) in the form of a vehicle tunnel. This road which extends to the French border allows passengers to access the French Sector of Geneva airport without having to travel through Switzerland. Vinci were appointed to undertake the works.

“BAT 1” – April 2016 to December 2017

This second infrastructure project extended the basement concrete shell of the Route Douaniène project the remaining 300m to the west to interface with the existing Terminal 1. Implenia was the successful tendering contractor.

“BAT 2” – April 2017 to July 2021

This final contract encompassed the building’s steel superstructure, cladding and entire fit-out. After an open tender, the contract was awarded to HRS. The contract had no contractor design elements so RBI-T, the design consortium, were entirely responsible for the “conception” of the project.

Superstructure

The specialist sub-contractor appointed to fabricate and install the steel superstructure was Martifer based in northern Portugal. Over 7’3000 tonnes of steel were transported from Portugal and, due to restrictions on tower cranes close to an airfield, the steel was installed on site using mobile cranes and mobile elevated work platforms. Pinned and bolted connections were prioritised to avoid site welding. The steel superstructure fabrication and installation respected the most onerous tolerances achievable thus ensuring that other trade packages such as the cladding could commence fabrication before the steelwork was in place.

Facades

Gartner was appointed as the specialist supplier of the inclined triple glazed façade on the pier and Sottas were responsible for the glazing systems associated with the rear service cores including the rainscreen with punched panels and single glazed stair cores.

The 2.5m wide by 5m triple glazed panels weigh 1.3 tonnes. Two of these panels are vertically arranged to form a seamless façade inclined at 26 degrees to the vertical along the airside and landside elevations. The longitudinal slope along the pier was very slight (0.3%). This required that the glazed panels step in section such that the mullions are vertical with steel pegs that transfer the load of the triple glazed panels onto the steel frames. The transoms follow the slope and conceal the stepping arrangement of the rectangular glazed panels.

Both the inclined frames and external windposts span vertically between the two structural levels – departure level and the roof. A flexible joint was designed between the steelwork of the arrival’s mezzanine, suspended from the roof above, and the façade system to prevent the passage of smoke. This joint is designed to accommodate the accumulation of structural tolerances, wind loading and live deflections.

The use of mock-ups and prototypes enabled a collaborative design process between the design team and the contractor and to engage the client in the decision-making process.

Services

The concept of the services strategy was based on a gate-by-gate distribution with each 80m of pier being autonomous. The coordination of the services needed to be of the highest order given the space constraints and the visibility of the services in the passenger spaces. The design principle was that the services would be distributed from the rear cores where the passenger toilets, plant rooms and service risers are located, out into the pier and from there bifurcate along 40m of the jetty where they would meet the service runs from the next gate. The visible electrical, mechanical, plumbing and sprinkler distribution in the ceiling void were rigorously coordinated to ensure that the limited space through the lateral steel trusses was used efficiently and precisely choreographed. Unusually the mechanical ducts are used both to extract air during normal operation and to draw smoke in the event of a fire thus avoiding duplicating ducts.

The large plant rooms required to service a pier of this size are invisible to the passenger as they are located underground in the basement that extends over 500m below the apron level. The civil engineering required to create this infrastructure was encompassed by the Route Douanière and BAT 1 contracts.

Internal Packages

An important internal package was the fire-rated glazing that separates different smoke compartments while letting in daylight offering fantastic views through the building for passengers. The pier’s floor finish is granite, sourced from Portugal and laid on a calcium sulphate raised floor with extensive cable routing located in the void. The ceilings have the primary role of providing cooling while also adding a touch of colour to the interiors.

Bespoke stainless-steel totems were designed to perform different tasks such as housing passenger information displays, accommodating the Rolex clocks designed specifically for the Aile Est. Most totems are designed to introduce fresh air to the departure lounges, while others are designed as discrete recycling bins. Way-finding signage was painstakingly designed and placed to enhance the departing or arriving experience by enabling passengers to find their destination with the minimum of stress.

Photovoltaic Array

The last elements to be installed on the pier was the photovoltaic array that extends the length and width of the pier’s roof. A conceptual rigour was required throughout the design process to ensure that the roof space was left free of plant equipment. Plant equipment would have broken the continuity of the array and thus the efficiency of the electrical production.

Practical Completion

Practical Completion was reached in July 2021 with the pier operational in December 202, in time for the peak winter season.