What is the future of urban design in the 21st century? This was the key question addressed by the International Building Exhibition IBA Hamburg in Northern Germany, which ran until 2013 and delivered a wide variety of projects and other innovative contributions to the contemporary urban development debate.

 

An urban center gets ecologically and socially balanced

The 60-plus building, social and cultural schemes were implemented in the IBA project area on Hamburg's Wilhelmsburg river island, the neighboring Veddel district and at the Harburg Inland Port. The project set out to demonstrate how a major urban center can achieve ecologically and socially balanced growth in the 21st century and thereby serve as an example of sustainable, forward-looking urban development.

 

Refresh the district

Hamburg's new State Ministry for Urban Development and the Environment (BSU) building, developed by the city’s property management company Sprinkenhof GmbH, stands as the urban centerpiece in the refashioned Wilhelmsburg district. The BSU, when it moved to one of Hamburg's most modern buildings on the island of Wilhelmsburg between the northern and southern arms of the river in May 2013, became the first ministry to implement the long-agreed initiative of making the "leap across the Elbe". This policy has cleared the way for growth of the city state at a central location. A 54 m tall central high-rise housing the main entrance is adjoined by two meandering blocks running to the north and west.

 

30,000 ceramic units in 20 different colors

One particular highlight – and a signature element in the work of Berlin-based architectural practice Sauerbruch Hutton – is the variegated facade design of the 13-story tower and the two attached five-story blocks, featuring some 30,000 ceramic units in 20 different colors. A further particularity of the scheme is its ambitious sustainability and energy concept. This was designed to meet the requirements of the DGBN (German Sustainable Building Council) certificate in gold, which it duly received.

 

Reliable roof waterproofing despite unconventional geometry

Aside from the striking facade composition, the unorthodox architectural concept also had implications for the roof in that the entire assembly had to be adapted to the undulating geometry of the building elements. The first step was to install bituminous vapor barriers and thermal insulation on the reinforced-concrete slab. This was then covered by a Sarnafil TG 76-18 Felt polymer-sheet roof membrane supplied by Sika Germany. When fully bonded, this product is also suitable for
gravel-ballasted and green roofs thanks to its certified root and rhizome resistance
under the FLL (German Research Society for Landscape Development and Landscaping) testing scheme. Given that the plasticizer-free, recyclable and extremely durable membrane also enhances the sustainability performance of the
roof system, it contributed to the achievement of DGBN gold certification.

 

Nonwoven backing serves as a bonding and levelling layer for full-surface adhesion  

The waterproof sheet membrane comprises a glass-nonwoven interlayer with a nonwoven backing that serves as a bonding and levelling layer for full-surface adhesion. The entire roof assembly was bonded with Sikaplan C 300 adhesive. Due to the building height, certain sections incorporated Sarnafil TS 77-18 membranes mechanically fastened with the Sarnabar system. All roof areas were then extensively planted. The Sarnafil TS 77-18 membrane likewise meets the stringent FLL requirements.

Signboard:
Owner: Sprinkenhof GmbH, Steinstrasse 7, D-20095 Hamburg
Architect: Sauerbruch Hutton Generalplanungsgesellschaft, Berlin
Lead designer: Obermeyer Planen + Beraten GmbH, Hamburg (from HOAI Workstage 5)
Construction period: December 2010 to May 2013
Applicator/Flat roofing: Werder Bedachungen GmbH, Leutersdorf
Parking lot roof:            Carstens Bedachungsgeschäft GmbH, Rotenburg/Wümme
Awards: DGNB (German Sustainable Building Council) certificate in gold, BDA (Association of German Architects) Architecture Prize, 1st place

Get more information about Sika Germany.

Watch the building complex from the air.