This thesis studies the Modern Malls in the Netherlands that were formed in the 1960s. The problem with these malls is that they have changed through time to keep up with the changing demands of the users, a development that has changed the once open ex¬troverted malls into introverted closed struc-tures. The closed structure of these malls, combined with rising vacancy and the ever-changing behaviour of the mall users, results that the malls in the Nether¬lands are struggling to survive. By analysing the open forms introduced by Sennett, the aim is to develop an intervention method to open op the modern mall. The interventions show that the open forms relate to different sca¬le levels depending on the intervention. The materialisation and architectural elements play an important role in the effectiveness of using open forms as intervention methods in Modern malls in the Netherlands.