Maastoren

Prior to the construction When the Dutch branch of Deloitte wanted a new headquarters, it chose the current location of the Maastoren. Both companies chose OVG as the developer of the new office building. Dam & Partners Architecten designed the Maastoren with Odile Decq Benoit Cornette. Also, engineering firm Zonneveld and the company Techniplan Adviseurs were involved in the developing process. Besix was the main contractor, and received €67 million for building the Maastoren. At the end of May, alderman Hamit Karakus said to the council that the Maastoren would be built and that the municipality would listen to the objections. The council agreed with the construction in the following month. As a reaction, Vereniging Woon- en Leefklimaat Kop van Zuid/ Noordereiland (Dutch for Association Living Environment Kop van Zuid/Noordereiland) filed a lawsuit against the municipality of Rotterdam. The association aimed at preventing the Maastoren from being constructed, and was previously known as Comité Maastoren Nee! (Dutch for Committee Maastoren No!). 200 objections against a license had been filed, mostly because of the height of the Maastoren and the above ground parking garage. Construction The process of making the site ready for construction started at the end of July 2006, but the preparations were shut down two weeks later on 3 September. On 21 September, the preparations were continued. The digging of the foundation started the following month. Part of the construction site was kept dry using sheet piles, because that part was situated in the river. In November 2006, all the remaining objections against the Maastoren were rejected by the general committee on objections of Rotterdam. The lawsuit against the construction, however, was still ongoing. On 25 April 2007, the groundbreaking took place. Ivo Opstelten, who was mayor of Rotterdam at that time, hammered the first pile into the ground. Back then, the opening of the Maastoren was planned in 2009. Meanwhile, the judge had given the verdict in the lawsuit of the association against Rotterdam, that was filed to stop the construction. The judge said the license was justified, and thus the municipality had won the lawsuit. On 27 May 2009, the Maastoren was topped out. At that time, all floors up to the twentieth floor were completely finished. To celebrate this occasion, alderman Hamit Karakus and CEO of OVG Coen van Oostram abseiled down the building to the 31st floor two days later. The construction was completed in November 2009. Opening and sale The Maastoren was put into use on 15 March 2010, and was officially opened two months later on 28 May. OVG, the developer, received a plaque from the Council on Tall Buildings and Urban Habitat. The plaque states the Maastoren has a height of , and is the tallest building in the Netherlands. The plaque is displayed in the lobby of the Maastoren since the opening. During the opening, Ahmed Aboutaleb, the mayor of Rotterdam, received a copy of the book Maastoren about the building, which was published by the Rotterdam Skyscraper Foundation. In December 2014, the American real estate company NorthStar bought a portfolio, that consisted of eleven office buildings including the Maastoren, from SEB Asset Management. NorthStar paid €1.1 billion for the entire portfolio. == Architecture ==

The Maastoren is designed by Dam & Partners Architecten. Also, the architecture firm Odile Decq Benoit Cornette was involved in the designing progress, and architecture firm OTH designed the interior of the office building. Also, the Maastoren has a glass extension. The strength of the building is provided by a core with two inner walls, by other inner walls perpendicular to the core, and by the exterior that consists of prefab elements. These parts are made out of concrete. The base of the Maastoren is situated on a layer of sand, that is situated on layers of clay. The foundation consists of almost 500 piles, on which an almost thick foundation plate rests. The underground parking garage starts on top of that foundation plate. The color of the Maastoren changes gradually as the building rises: the building is colored dark grey at the bottom and silver white at the top. To create these color changes, the panels at the bottom are made of dimension stones and the panels higher in the building are made of 22 shades of aluminium. The dark grey dimension stones at the bottom are meant to resemble the basalt wharf. Also, the building has a dock for water taxis. The water from the river is used to supply the fire sprinkler system as well. Also, the ground floor includes a reception, waiting space, meeting space, space for informal meetings, and a bar that bears the name Grand Café. Most of the parking garage is above ground because of the small size of the lot and because of the high costs of a deep underground parking garage. The building has twelve elevators (including service elevators), of which two glass elevators are situated on the exterior to reach the above ground parking garage. The three fastest elevators, that serve the top floors, can reach a maximum speed of around . Height The architectural height of the Maastoren is , but there's a mast above that height that isn't included in the architectural height. The total height with the mast included is . The highest occupied floor is located twenty metres under the top at above the ground. == Maastoren Challenge ==

The Maastoren Challenge is a sporting event inside the Maastoren, that has been held in 2013 and in 2015, to raise money for charity. The competitors start at the bottom of the office building, and have to reach the top of the Maastoren by using the stairs only. The 2013 edition was held on 23 November and the 2015 edition on 18 April. == Awards ==

The Maastoren has received two awards: De Vernufteling, a yearly engineering award, in 2007 and the FGH Vastgoedprijs, a biennial award, in 2010. De Vernufteling was awarded to Techniplan Adviseurs because of the heating and cooling system of the building, that uses seasonal thermal energy storage. == References ==