IJburg is one of Amsterdam’s big new urban neighbourhoods extending over seven artificial islands with accommodation planned for 45,000 people. In autumn 2007 work began on the »Solids«, a perimeter block development consisting of seven buildings, located at the entrance to Haveneiland, the largest of the islands. This scheme combines a very high building density – the specified floor area ratio of 6.4 is comparable to that for high-rise neighbourhoods in Asia – with a ground plan allowing for flexibility of use. The appearance of the ensemble is reminiscent of traditional urban business premises with colonnades, punctuated façades, balconies and imposing stone facing. By contrast, the interior of the buildings is almost radically minimalist with a view to permitting the maximum leeway in the use and division of the space. The pre-cast concrete skeleton construction, stairwells grouped in cores and ceiling heights of four or six metres ensure that the space can be divided up to suit individual needs. All the built-in units can be removed and load-bearing partition walls are not required for static equilibrium. The structural framework is designed for longevity, whereas the technical infrastructure is variable and readily adaptable to valid standards. The building itself, as a »shell« devoid of any specific function, merely provides a framework that every tenant can fill as needs dictate. The loft-like units up to 20 metres deep can be used as offices or as hotel space, medical or legal practices, social amenities, studios or apartments. This leaves scope for individual design and easy adjustment to changing requirements such as urban diversity and sustainability of use. The term »Solids« is intended to reflect the durability of the buildings as well as their functionality. That it also encompasses high-quality architecture is apparent from the impressive façades and the elegant foyers as well the careful selection and details of the materials.