The Maastoren is a 165 meter tall skyscraper in Rotterdam. It is the tallest skyscraper in the Netherlands. The building was designed by Dam & Partners in cooperation with Odile Decq Benoit Cornette and is 44 stories high. The building is mainly used as office space. It also contains parking space (10 stories above ground and 2 stories below ground. Deloitte, AKD Prinsen van Wijmen, Mabanaft and Q-Park rent space in the building. The Maastoren has a special durable heating and cooling system which strongly reduces the building's carbon dioxide (CO2) emissions. The system uses water from the river Maas and energy storage in the soil. Techniplan Adviseurs from Rotterdam, won a De vernufteling prize for the system's design. Construction started in October 2006. On 9 December 2009 the building was finished.