This PhD thesis provides an analysis of central processes related to the creation, negotiation and communication of the future sustainable building in Norway. Both researchers and practitioners have pointed at the Planning and Building Act as a central means to speed up the process and to set the frames for a sustainable development. Based on interviews with experts, I conclude that the building laws are never a direct translation of research results, EU directives and international agreements. These have to be translated, adapted and mediated, i.e. domesticated, to the Norwegian climate and cultural conditions. Particularly in Norway, building researchers consider the Passive Houses (PH), extra-low energy buildings with a focus on energy efficiency, as a necessary step in a sustainable development of buildings. A closer scrutiny of the PH development in Germany and Austria helps us to understand and describe the factors that have made the voluntary PH standard a success in these two countries. However, the initial political support for the Norwegian PH standard as technical requirement ignited a controversy among engineers, architects, physicians, physicists, policy-makers and practitioners. In the analysis of this path-dependency controversy I conclude that the disagreements address the technological concept but also its implications in society, health, culture, research and education. The knowledge produced in the research environment and the political decisions are brought to a broader public by the media. The analysis of newspaper articles on low energy concepts reveals that the media in Norway has relied heavily on experts’ knowledge to mediate the news: also the mediation of the sustainable building has become an expert task, with little public scrutiny.

This paper shows how much electricity generation would be needed for a passive house to achieve a zero emission balance over the year, hence to become a Zero Emission Building, ZEB. The case study is based on the passive house apartment blocks built in 2008 in Løvåshagen, near Bergen, Norway, and the analysis focuses on the consequences of adopting different heating systems. With the carbon emission factors assumed, it is shown that the sole PV installation on the roof is generally not sufficient to generate all the electricity needed to achieve the ZEB balance. Possible integrations are the use of PVT panels (to better exploit the limited roof space), adopting of a centralised cogeneration of fuel cells fuelled by biomass or biofuel, or increase of the generation capacity by adding extra PV area (e.g. on the garage roof) or a mini wind turbine.

Moving away from the annual energy budget and including the emissions of the entire building lifetime during construction, operation, and disposal is a key aspect of ZEB. This can be summarised in an emission inventory of operation and building components and services. The aim of this paper is to investigate the emission balance of both operational and the embodied energy in different highly energy efficient buildings concepts which are worth considering toward achieving Zero emission buildings. In this work four concepts for energy efficient buildings are identified which could provide stepping stones towards a definition of ZEB. These concepts were applied to a generic model (´shoe box model´) of a detached house. The greenhouse gas emissions in kilogrammes CO2 equivalents over buildings lifetime due to embodied and operational energy were accounted for three possible approaches towards achieving a Zero Emission Building. A reference building was used as a base case which is a passive house with reference materials used in the commonly used Norwegian construction. The first alternative aims at zero operational energy disregarding the embodied energy in the materials. The second alternative tries to reduce the embodied energy based on \'low emission\' material choice, without efforts to improve the energy performance. Alternative three combines both measures from alternative 1 and 2. When applying the UCTE electricity mix, representing the present electricity infrastructure, clearly most emissions are related to operation. Therefore alternatives 1 and 2 without operational emissions have significantly lower emissions. Applying other electricity mix representing a de-carbonised electricity grid, the differences are less distinct. And since electricity is also part of the emissions of building materials as electricity factor for the production the results might align even more. Hereby also the location of production gains increased importance. Windows, foundations, slab to ground, floor slabs of the building components and sanitary installation, ventilation system of the building services show high emissions in all four cases. Two main reasons can be identified – lifetime and emission-intensive materials. Lifetimes of components and services have a crucial impact and must be defined clearly. Especially windows and building services have short individual lifetimes and require replacement when considering the entire building\'s lifetime. The use of the same material or unit may lead to an overestimation of emissions. However, the prediction and application of ´better´ future products and lower emissions due to improved production and a de-carbonised energy supply appears problematic. More important might be the handling of the replaced items. Cradle-to-gate conditions do not allow an appropriate treatment in this case.