There are two photographs here. Aravena provided a concrete frame, with kitchen, bathroom and a roof (left), which were designed to allow families to fill in the gaps (right). So, the architect provided a basic concrete frame, complete with kitchen, bathroom and a roof, allowing families to fill in the gaps, and stamp their own identity on their homes in the process.Photograph: Cristobal Palma, Source: www.theguardian.com