The building formerly housing the Faculty of Geodesy at Delft University of Technology had to be renovated to accommodate the laboratories and offi ces of the Netherlands Institute for Metrology and Technology (NMi), including the Van Swinden Laboratories.By placing the laboratories on the ground Floor, vibrations from other building functions are kept to a minimum. In order to safeguard fl exibility, the lab-specifi c installations have been placed on the fi rst fl oor, immediately above the laboratories. The main entrance is also found at this level so that logistical fl ows of public and personnel can be optimally regulated.Despite, or perhaps even thanks to, the restricted budget and tight planning, the renovation design has maintained a strong sustainable characteristic. In addition to the fact that renovation is the ultimate form of re-use, maximum use has been made from already existing materials. Thus the existing facade, including framework, was not demolished but was improved to a better performing facade which enabled a more comfortable indoor environment. The glass casing around the building creates a cavity that is ventilated with a combination of natural draught and the venturi effect. This helps to keep the heat out of the buildingin the summer and prevents heat loss in the winter – and thus leads to considerably improved energy performance. A surprising new area has also been created by placing balconies in the accessible cavity, close to the informal meeting areas.