The alternative to a zero energy apartment building including the photovoltaics installed in the façade in this project, would be an ordinary apartment building constructed according to the building code. Because of the infancy of zero energy buildings in general and the application of photovoltaics integrated into façades, demonstration projects are considered to be vital to their further uptake.

Guided by internal energy efficiency policies, the housing association decided to invest in two zero-on-the-meter apartment buildings, which include photovoltaics integrated into the façade of the buildings. The buildings are depreciated over a period of 50 years. However not all the investment costs are covered by the project. Financial resources were made available by the housing association to construct a demonstration project. At least 50% of the additional investment in sustainability needs to be covered by rent and the Energy Performance Fee. The Energy Performance Fee has been introduced by the government to overcome the split-incentive problem, i.e. the gains on the energy bill of tenants are paid by a fee to the social housing association to cover the investment in energy efficiency technologies.

The following key factors affected the case: 1. Energy efficiency policies stimulated the uptake of sustainable technologies by social housing associations. However, energy efficiency policies tend to differ among social housing associations as a result of local conditions. 2. Lowest price procurement policies are not conducive to partnering concepts and therefore hinder the uptake of sustainable technologies. 3. Financial resources to invest in sustainable technologies – often linked to learning costs – are stimulating the uptake of sustainable technologies 4. Despite the energy performance fee it remains challenging to communicate with tenants about the fee. Moreover, the legal implications of the energy performance fee are not fully understood by either social housing associations or the housing industry. 5. A lack of knowledge about the legal conditions and subsequent decision-making processes within the social housing sector complicates the collaboration between social housing associations and the housing industry. 6. The social housing association involved in the case project invested in building organizational capabilities, i.e. the knowledge and skills, necessary to adopt and implement sustainable technologies in the project.