The ‘Geldershoofd’ building was originally designed as a modular construction. It is fit only for the function for which it was initially intended. Because of the limited strength of the foundation no extra load can be carried. A proposal for strengthening will be shown. Possible measures to stabilize a part of the building after creating bigger openings in the building, such as those used for the 'Hoge poorthuis' are also considered. Finally, the solution for extending floors to the outside of the original facade with the aid of the existing cantilevered concrete beams will be described. The cantilevered concrete beams alone are not strong enough to carry the new floor load.