The importance of preserving - and not merely transforming - a structuralism building, a topic of debate since original intentions were to create freely adaptable buildings. Many designers have proposed transformation schemes but few have investigated full restoration plans. Where should the balance be found? The site of intervention chosen is the Humanities Faculty of the Arts campus of Leiden University, original architect Joop van Stigt (1982). Two reasons to motivate a design intervention on this site are: a) to solve critical technical problems around the building structure and b) to facilitate a more experiential learning and interactive working environment for all students, lecturers, staff and visitors. Here I aim to test two approaches to find out which approach/ position will preserve the old spirit of structuralism and reflect back concepts and spatial qualities with the new inserted interventions. The hypothesis is to see what is gained or lost if one layer around the building structure (skin/surface) is sacrificed? The method followed in the test is to place one design position on the campus' north cluster and the other position on the campus' south cluster of the Wittesingel Campus. An evaluation shows how one position offers a greater potential to preserve the spirit of the 1970s /1980s structuralism movement. The most significant finding in adapting the skin of the buildings on the campus’ north cluster, is a total transformation of the external appearance. All the individual units now appear outside as one building although inside as a cluster of individual “houses”. However by adapting the interior surface of the “houses” on the campus’ south cluster will drastically transform the inside experience of the working and learning. On the campus’ south cluster, many original material finishes are lost while the exterior brick skin façade appearance remains intact. The design of the campus’ north campus revealed that the original structure could extend itself vertically and horizontally in a new life as intended by structuralist architects. Concluding that the structure can be updated to accommodate a new infill of spaces to learn and interact between structural components and the carefully detailed, robust, rough material finishes are easy to combine with a similar range of soft colours and texture furniture for an inspiring knowledge center and sustainable 21st century Humanities Faculty Campus of Leiden University.