The building sector consumes about 40 % of the total global primary energy, 60 % of the total electricity and accounts for about 30 % of all greenhouse gas emissions (UNEP, 2015). The zero energy building (ZEB) concept is considered as a step towards reducing the environmental impact of the building sector (European Parliment, Council of the European Union, 2010). This work has reviewed the concept of ZEBs by looking at three different definitions available in Sweden: nearly ZEB by Boverket (the Swedish Board of Housing, Building and Planning), ZEB by Sveriges Centrum för Nollenergihus (SCNH), Swedish center for ZEBs, and net primary ZEB by Skanska. The proposal by Boverket may form a basis for the statutory requirements for all new buildings in Sweden after 2020. The work also comprised a performance analysis, as well as a review of the development process, of terraced houses in Sweden built by Skanska according to their net primary ZEB definition.The overall objective was to facilitate the implementation of future ZEB projects. This was done by highlighting differences among the three definitions and how the implementation of Boverket’s proposal will impact other definitions. The performance analysis and process review pinpointed problem areas, acknowledging both technical, social, and economic aspects linked to the ZEB concept, which can be improved in order to successfully implement ZEBs in the future.To compare the definitions, a framework developed by Sartori et al. was used (Sartori, et al., 2012). A deductive approach was then used where a numerical analysis of one the terraced houses energy system was compared to simulations. The focus for the definition and performance analysis was the energy use of the building. In order to take other perspectives into account, the occupant experience as well as the building development process were investigated. This was done using an inductive approach by conducting semi-structured qualitative interviews with occupants and employees of the construction company.The ...