An analysis of the building stock [2] shows that the category ‘terrace dwellings’ built between 1945 and 1975 makes up a major part of the total building stock, both in respect to number of dwellings and energy consumption. In the next decade, these dwellings will be in need of renovation. For these reasons, this type of dwelling is selected as the object for the renovation concepts.

The annual energy consumption of such a dwelling consists of approx. 2.000 m3 of natural gas (for space heating, DHW and cooking) and approx. 3350 kWh of electricity. It is assumed that there is no need for cooling in these dwellings in their current state nor will there be after renovation. In terms of primary energy (denoted with the index p), the total energy consumption adds up to 260 kWhp/m2a, shown by the left bar in the graph in figure 1.

The target of the RIGOUREUS project is to reduce this figure by 75% down to 65 kWhp/m2a. To put this into perspective, in order to obtain the Passive House quality mark, the primary energy consumption of a Passive House must be less than 120 kWhp/m2a. The ambition of the RIGOUREUS project therefore is almost twice as high as the Passive House quality mark.

The middle bar in figure 1 shows the energy demand of a terrace dwelling after the energy demand for space heating has been reduced to 25 kWh/m2a by the application of the Passive House concept and the energy demand for DHW has been reduced by a factor of two by the use of a solar collector. As figure 1 shows, these measures do not suffice to reach the target. The remaining energy consumption is now dominated by the domestic electricity consumption. This too should be reduced by approx. a factor of 4 in order to reach the target of 65 kWhp/m2a, as shown by the right bar in figure 1. In fact, the issue of reducing the domestic electricity consumption is all the more important because in The Netherlands, as in the EU, electricity consumption shows an increasing trend of approx. 2% per year between 1990 and 2006 [3] and it is expected to further increase in the future.