Currently, clear European and Global climate goals, such as the Paris Agreement and the European Energy Efficiency Directive, are in place to stimulate more efficient use of resources and lower emissions. The built environment can play a significant role in reaching these objectives in the future since it consumes around 40% of the total energy consumption (Šjan, 2016). Also, approximately two-third of the existing stock in the Netherlands will be in use within the timeframe of these goals. Therefore, a major challenge is to adapt the existing stock to become more energy efficient or even neutral. The Dutch government obliges office space to have at least label C by 2023 (RVO, 2018). Real estate technologies can enhance the energy efficiency of these buildings by providing data on actual energy consumption. Nowadays, an energy performance gap exists between the actual and theoretical energy consumption stresses the need for more insights on a building level (Sipma, Kremer & Vroom, 2017). Therefore, this research investigates to what extent this energy performance gap can be bridged by adaptations to the existing office stock in the Netherlands and what possible drivers and thresholds are for different stakeholder. A literature study has provided input for the development of a theoretical framework and the selection of the research methodology. A case study research has been conducted to underperforming office buildings in the Netherlands. Four case studies were conducted based on their energy performance gap, two buildings of energy label A and B will be researched. The research is focussed on buildings characteristics and stakeholder attitudes towards certain adaptations, either structural or behavioural. Findings of this research indicate that structural adaptions are rarely preferred by the investor due to possible loss of value. Tenant often lack insight into their own energy performance and are therefore unaware and unable to make decision on behavioural adaptions. A framework has been developed that provides steps to take fostering the process towards more sustainability in the built environment.