The latest striking creation from the Office for Metropolitan Architecture (OMA) opens to the public today (11 December) in the Dutch city of Rotterdam.

Designed as a series of pixelated steel and glass cubes that appear to float skywards, the Timmerhuis is a mixed-use complex housing shops, restaurants, cafes and Rotterdam’s city museum.

The building is a merge between a 1950s municipal office block – which now forms the interior walls – and the entirely new modular structure, formed of 3.6m (11.8ft) high cubes that rise into two irregular peaks.

“The building’s formless, seemingly improvised composition acts as an echo of the city’s mood,” said the project’s lead architect and designer, Reinier de Graaf. ”It creates the possibility of different experiences. From one side the building appears nearly symmetrical, monumental even. On the other side, the same building appears delicate and accommodating.

“Rather than adding another grand statement to Rotterdam's ecology of successive architectural convictions, the typical mass of Timmerhuis seeks to subtly negotiate between the architectures of the buildings surrounding it."

The ground floor of the 48,400sq m (521,000sq ft) complex is home to a large public passage, retail space and the relocated Museum Rotterdam – which will tell the city’s story across 1,630sq m (17,500sq ft) of exhibition space.

The upper floors are occupied by office space and apartments with their own outdoor terraces.

The design brief stipulated that Timmerhuis must be the most sustainable building in the Netherlands, with a BREEAM level of excellence.

To achieve this, OMA added two large atriums, which act like ventilating lungs. They are connected to a climate system that stores warmth in summer and cold in winter and releases this energy as warm or cold air as required.

The building also features 14,000sq m (150,700sq ft) of glazed glass, and the facade uses hi-tech translucent insulation for high levels of energy efficiency.

OMA worked on the project with local architects ABT, structural engineer Pieters Bouwtechniek, sustainability consultants DGMR Bouw. The contractor was Heijmans and the interior contractor was Keijsers Lundiform. The budget was approximately €100m (US$109.6m, £72.2m), funded by the local government.

OMA, who are based in Rotterdam, recently won an international competition to design a cutting-edge £110m (US$166m, €157m) arts venue in the UK city of Manchester. Like Timmerhuis, The Factory will also be constructed using cube-shaped steel and glass components.