The DC Towers, also known as the Donau City Towers, is a mixed-use skyscraper complex in the Donaustadt District of Vienna, Austria. The towers were designed by French architect Dominique Perrault. Werner Sobek AG was responsible for the structural engineering as well as the facade and height access planning of DC Tower 1.
DC Tower 1, the tallest skyscraper in Austria at or including the antenna spire,DC Tower 1 was officially finished with an opening ceremony on 26 February 2014 attended by architect Perrault and former astronaut Buzz Aldrin.DC Tower 1 opening Due to the 2008 financial crisis, ground breaking was delayed several times. Eventually, construction was started on 17 June 2010.
As of June 2012, tenants were confirmed for 50 percent of the floor space according to the owner Wiener Entwicklungsgesellschaft für den Donauraum. Most of the available floor space will be used for offices. Baxter International has been confirmed as one of the largest tenants. The upper floors will be used for apartments, while the first 15 floors will house a four-star hotel operated by the Spanish Sol Meliá Group. There will also be a restaurant in one of the top floors.
DC Tower 2 will reach , making it Vienna's fourth-tallest building. It will house offices, shops and rental flats.
History Concept
The first development concepts for the site in Donau City were already in place in the early 1990s, but they were all rejected. In 2002, the WED (Vienna Development Company for the Danube Region AG) then announced an international design competition for this last section to be developed. The architect Dominique Perrault from Paris was awarded the contract in this expert review process. He was then commissioned to draw up a master plan for the area. Based on these plans, an urban development concept was drawn up and approved by the local council on 1 July 2004. In contrast to previous projects at the site, mixed use was prescribed here. Until a rezoning to in 2007, the maximum height of buildings on the site was . This value refers to the construction height with the antenna being excluded.
The vacant plot of land, located directly on the Reichsbrücke, was a prime urban development site; the prominent location at the entrance to Donau City required special utilization. A "landmark" that could be seen from far away was to be created. There were 120 different designs before the final concept was developed. Perrault designed two double towers as a "bridgehead" as a built entrance gate for the district. The design of the third tower was by the Vorarlberg office of Dietrich Untertrifaller Architekten.
The project was originally scheduled to start in 2007, but construction was delayed several times.
Construction phases The towers, designed by Perrault, are being built in collaboration with the Viennese firm Hoffmann-Janz Architekten. The civil engineering was carried out by Porr and the structural work by Max Bögl. A total of around 100,000 cubic metres of concrete and 17,000 tonnes of reinforcing steel were used. The total weight of the tower is 290,000 tonnes.
2010
The first activities on the then vacant site were already visible at the end of February 2010. The laying of the foundation stone and the start of construction finally followed on 17 June 2010. (orf.at, 17 June 2010) In November, the first pile drilling began and the first permanently mounted construction crane was used. In December, construction of the foundation was already in full swing. The settlement behavior in view of the location directly next to the overlay of the Danube bank motorway A22 and the proximity to the Danube required a special deep foundation. Under the base plate, which is thick in its core, diaphragm wall piles extend a further into the building ground. In the area of the base plate alone, 13,000 cubic meters of concrete were installed (this corresponds to the load of 1,625 concrete mixer trucks). The civil engineering work was completed in 6 months.
2011
The most progress was visible in 2011. Construction began at the end of March 2011, and the first underground floors were completed at the beginning of April. At the end of April, the first above-ground floor was built and the concrete core took on visible dimensions. There were now five fixed construction cranes in operation. At the beginning of June, the first fixed roof crane was assembled and the movable weather protection was attached. By July, the DC Tower 1 under construction could already be seen from every tall building in Vienna. In the same month, the crane on the left outside of the tower that grows with it was attached to the building, and the first freight elevator was installed on the west side of the tower. In August 2011, the concrete core disappeared into the growing building and the 13th floor was completed. Work also began on raising the glass facade on the west, north and south sides.Planungsprozess – Donau City , retrieved 6 December 2014.
In September, construction of the glass facade on the east side of the building began. Since then, the facade has been raised on all four sides of the tower to provide protection from wind and weather, but there was hardly any progress in the construction. This was due to the outrigger floors, which are intended to ensure the stability of the building. These were completed at the end of November, but the expected opening date was postponed from the beginning of 2013 to summer 2013 at the earliest.Dietrich Untertrifaller Architekten – DC 3 Tower, retrieved 15 May 2017.
2012–2013
From spring 2012, the tower started growing again. Roughly every 5 days, the tower grew by one floor. At the end of April 2012, work was started on the 32nd floor, which marks about half of the final construction height. On 25 October of the same year, the 60th and final floor was reached."DC Tower 1" kurz vor Dachgleiche 25 October 2012. According to WED, work was carried out six days a week. In late summer 2013, the last facade elements were being assembled. The two construction cranes that were still in use on the tower at the time were gradually dismantled. They had previously grown with the building over the entire construction period. One was attached to the outside of the supporting structure, the other was placed in one of the elevator shafts.DC Tower: Österreichs höchstes Haus 24 April 2012.DC Tower 1: Am Dach von Wiens "Burj Dubai" 15 May 2012. On 19 September 2013, the approximately tall antenna was finally brought into position using a special helicopter from Heliswiss. The building was thus completed externally.Hubschrauber finalisiert DC Tower orf.at, 19 September 2013.
Tower 1 opening The official opening ceremony of the hotel and tower took place on 26 February 2014. Guests of honor included architect Perrault, Vienna Mayor Michael Häupl, former New York Mayor Rudy Giuliani and former astronaut Buzz Aldrin.Höchstes Haus Österreichs eröffnet orf.at, 26 February 2014.
Tower 2 The DC Tower 2 is planned to reach tall. The significant difference in height between the buildings is also reflected in the different letters of "DC" in the construction project's logo. However, the start of construction was delayed several times, not least due to the 2008 financial crisis. In the spring of 2016, the building site for Tower 2 was sold to a German real estate fund.Donaucity: Perraults Türme lassen auf sich warten. (Die Presse, 21 November 2008)Baustart für DC-Towers verzögert sich (derStandard.at, 11 August 2008)
In March 2018, it was announced that the Vienna-based S+B Group had signed a general contractor contract for the second Donau City Tower with the owner of the property, the German company Commerz Real. The planned start of construction in 2019 was not met. In 2020, it was announced that Tower 2 would no longer follow the design of Tower 1. The reason given was that due to the proportion of apartments instead of almost exclusively offices as in Tower 1 as open spaces were desired and these would not be compatible with the wave design.ORF-Online: Zweiter DC Tower wird Mitte 2019 gebaut orf.at, 15 March 2018, retrieved 15 March 2018.
Construction began in 2022 and the development company expects completion in 2026.
Tower 3
The complex shares its area with the DC Tower 3, a residential serviced apartments regimed building constructed between 2019 and 2022.
Layout Development and security The access logic on the ground follows the Donau-City concept: pedestrian and traffic levels are on different levels. The main access to the complex is via the central roundabout of Donau City on the Donau-City-Straße named after it. The address is 1220 Vienna, Donau-City-Straße 7 . Tenants of Tower 1 can drive directly into the garage from this level, visitors and taxis are directed up to the access level -1. For better orientation, this was designed as an open space. This is where the hotel access and the entrance to the public underground car park are located. It has space for 354 vehicles. Deliveries and disposal take place via the central loading yard, which is also located on this level and is connected to the service elevators. The higher pedestrian level can also be reached via open stairs. There are separate entrances for the different user groups on this level.
The tower's security concept provides for the separation of the individual visitor flows, which is facilitated by the Donau City, which is laid out on different levels. The building is divided into individual security areas, in which the movement flows as well as the entrances and exits are controlled and monitored. In the reception areas, separation systems and in the elevators, intelligent control technology prevent the mixing of user groups. The distribution of people within the building is carried out via 29 elevators and two escalators. Two elevators are designed as full-fledged freight and fire service elevators with a nominal load of up to 2,500 kg. The DC Tower currently has the fastest elevators in Austria. At up to 8 m/s (around 29 km/h), the highest floor can be reached in 40 seconds.Kone Referenzen – DC Tower, retrieved 26 September 2014.
The public areas and hotel floors are accessed separately by four fully glazed elevators. However, a cantilevered spiral staircase is also installed in the base building. The main elevators in the tower are equipped with a destination selection system, where the destination floor is selected before entering the cabin. The system then directs the user to an elevator, thus enabling shorter waiting times and fewer stops. In the DC Tower, this system has been expanded so that the access controls are also connected to the elevator control. This means that the next elevator is assigned as soon as the passengers pass through the security gates.Kaba regelt den Zutritt zum höchsten Gebäude Österreichs 23 May 2014.
Usage