Building durable structures means creating sustainable structures. The more resistant a structure is to external influences, the more sustainable it can be. Durability describes the length of time a structure will last with or without maintenance. Sustainability, on the other hand, aims to fulfill the needs of the present without restricting the possibilities of future generations. 

But what if the needs of future generations differ from those of today ? Can a long-lasting structure be flexible enough to enable this change ? Only by disentangling structure and use can a building retain long-term relevance and avoid demolition. This work examines the concept of a long-lasting, flexible structure - a framework or prototype that is not monofunctional, but gains flexibility through flexibility of use . The aim is an architecture that can adapt to technical and usage-related adaptations. This will be tested using a prototype design for a Berlin vacant lot, inspired by the typology of the Berlin apartment block, which is an example of longevity. 

The design shows on different floors in the front and rear building how a offen floor plan can respond to future changes of use. The very central component is the use-neutral space: a square, 25 m² area with no defined use. These spaces are deliberately flexible and invite residents to personalise their design rather than dictating predefined functions. This creates a structure that is dependent on the active appropriation of the residents and thus becomes a dynamic, contemporary living space. In terms of design, the building is monological and has few layers, which makes the basic structure more robust and less prone to errors. This raises the fundamental question: if we have to build anew - and we will - how should we do it?