The New Norwegian building regulations (TEK07) describe two ways to fulfil the new energy regulations for a building; the Energy measure method and the Energy target method [11].

The target method is based on net specific energy demand per year, the efficiencies of the energy systems are not taken into account. Passive measures that reduce the net cooling demand will contribute to satisfy the energy frame. This puts an extra focus on utilizing passive measures to decrease the total energy use in buildings. The regulations still contain minimum requirements concerning the U-values and air tightness of the building envelope which help to maintain a good insulation standard [11].

1.2. PH

Particularly in the residential sector the passive house standard has become widely used [10]. Although the passive house standard is well defined in residential buildings in Germany there is still no official definition for Nordic countries [3]. Today, it is not clear if the passive house standard can be used as a design guidance for office buildings [14].

2.3. ZNE

There is no definition of a zero net energy building. Torcellini et al. (2006) provided an overview of the various approaches [13]. ‘A net zero-energy building (ZEB) is a residential or commercial building with greatly reduced energy needs through efficiency gains such that the balance of energy needs can be supplied with renewable technologies. ’ Torcellini et al. (2006) used this as a definition but they also indicated that ’ …we lack a common definition, or even a common understanding, of what it means. ’

In this paper, the annual operational energy consumption of a building according to NS 3031:2007 is balanced with annual on-site energy production. It has been used for calculating on-site electricity and heat production without looking into storage and grid connection issues. This

approach does not take into account the daily and seasonal mismatch between demand and supply of energy. Results of an annual net energy balance can thus only be an indicator for energy concepts and cannot be used for detailed energy design.