Terminal 4 at Barajas Airport is one of the places I frequent a lot. Madrid is where I used to live, where my family is and every time I travel I stop in this city to say hi at least (even if it is just for one day). Gate U69 feels like home already (the Chicago flight departs from here) and I get the feeling that all my new stories and every happy phase of my life started here.
I have quite a personal relationship with this building but it also happens to be a remarkable piece of architecture as well. The following is a very detailed description of this building and its construction.
Have you ever been here? What were your thoughts about it?
The project for Terminal 4 at Barajas Airport was won in competition by a consortium of Richard Rogers Partnership, the Spanish practice Estudio Lamela and two engineering companies TPS (UK) and Initec in 1997. It is an architectural and city planning complex with 42 million passengers per year making this airport the 5th busiest of Europe. The main components of the design include parking facilities, a terminal building and a satellite or midfield terminal building. The design team was also required to incorporate automatic baggage handling systems, automatic people movers to connect the terminal with the satellite, as well as a train and metro station. Construction started on 2000 and it was completed on 2004.
Barajas is a model of legibility, with a straightforward linear diagram and a clear progression of spaces for departing and arriving passengers. The accommodation is distributed over six floors; three above ground for check-in, security, boarding and baggage reclaim, and three underground levels for maintenance, baggage processing and transferring passengers between buildings. The lower levels of the building, robustly constructed in concrete, contrast strikingly with the light-weight transparency of the passenger areas above.
Model that shows the concept in layers
The construction of the Barajas Airport terminal has been undertaken in three construction layers – the basement which drops to as much as 20 metres (66 feet) below ground in some places, the three-story concrete frame above ground, and the steel-framed roof.
In a bid to limit the height of the building, post-tensioned concrete beams restrict the depth of the beams to only 90 centimetres (three feet). The beams were cast in lengths of 72 metres (236 feet), with concrete planks used to span between them to create the 18 by 9 metre (60 by 30 foot) grid. Here you have several pictures of the construction process.
Above, the concrete tree trunks on the top floor provide fixed base points for setting out the roof steel work. The structural system for the roof works outwards from the tree trunks where four inclined branches prop a pair of double-S modules. In this way, each pair of tubes plus the roof steel stabilise the roof structure in both directions.
The roof passes over the cladding line at the edges of the building, emphasising the roof rather than the facade. The building is covered by a ‘wave’ roof supported on central ‘trees’ and is punctuated by rooflights that provide controlled natural light throughout the upper (departures) level of the terminal, and oversailing the edge of the building to shade the facades.
Given the multi-level section, a strategy was also needed to bring natural light down into the lower levels. The solution is a series of light-filled ‘canyons’ that separate the parallel slices of space that denote the various stages of transit, from the arrival point, to check-in, security and passport control, to departure lounges and finally to the aircraft.
The facade structure is in the form of cable ‘kipper’ trusses at nine metre (30 feet) centres. A pair of cables begin at a common point at ground level, one arcing in and one out, held apart by compression struts that also support the horizontal glazing mullions. As the cables approach the roof they come back together, held by a V-bracket, making a fish outline, hence the name ‘kipper’ truss. A ‘jacking’ system was used between the roof and terminal floor during erection which when released ensures that adequate permanent tension was introduced in the cable trusses.
To further reduce the visual impact of the facade, shading is not introduced at the cladding line but is hung from the roof overhang which is propped with elegant Y-shaped props at the ends of each module.
Constructive detail of the façade
The facades are protected by a combination of deep roof overhangs and external shading. A low energy displacement ventilation system is used in the pier, and elsewhere a more conventional high velocity system is used.
Despite the extreme heat of summer in Madrid, the design team were committed to the use of passive environmental systems wherever possible, while maximizing transparency and views towards the aircraft and the mountains beyond. The building benefits from a north-south orientation with the primary facades facing east and west – the optimum layout for protecting the building against solar gain.
Natural Light: Is provided by the glass façade and by the rooflights.
Artificial Light: Is maximized by the mirror system that reflects light.
The heavily insulated roof is clad in laminated strips of Chinese bamboo, giving it a smooth, seamless appearance.
Natural stone is used as flooring throughout the terminal, adding to the seamless integrity of the space.
The concrete work is in-situ, although special attention has been focused on areas where the concrete will be visible, such as the edge strips to the canyons in which steel shuttering has been used.
The facade is supported by a series of tensioned trusses,. Horizontal aluminium fins span between the trusses on which the high-performance glass is fixed. Heavy vertical support members are avoided and the result is a seamless horizontal aesthetic underlining the main axis of the building.
A simple palette of materials and the use of a kit-of-parts approach to detailing reinforces the direct simplicity of the architectural concept as well as facilitating the ultra-rapid construction programme and maximizing the potential for flexibility. The building can be read as a series of extrusions, potentially infinitely extendable, rather than a free-standing bespoke composition. The sheer size of the building has been the key to the assembly-focused approach. A flexible, loose-fit system employing large-scale modular repetition on an 18 by 9 metre structural grid was chosen as the best solution to accommodate the multitude of uses in the terminal.
Some details of the building are especially outstanding. Besides the careful constructive details shown before, the HVAC is curiously integrated on each space. Either close to the façade or on open double spaces, not many people find the air disposition. Here you have some examples.
In my opinion, this is a very remarkable building. Despite all the legal barriers and all the security measures (of which some of the were new), the team solved the problems in a very smart way and in a very reasonable amount of time. Very few projects of this size turn out so well. The Barajas airport is a building that works and on which people feel comfortable. If you wish to read further you can here download the Construction Report by Estudio Lamela (Spanish) or read about the project on Richard Rogers web here (English).