Dear Valuethinker An english version of the passivhaus information is available here. http://www.passiv.de/index_10PHI.html - click the british
flag top right.
The energy use in the Passive haus Kranichstein (Passivhaus)
the diagram to the right at http://www.passivhaustagung.de/Kran/Passivhaus_Kranichstein.htm gives annual (final)energy consumption per m2.

Heating      10.5 kwh
Hot water     7.2 kwh
Electricity  14.7 kwh
total 32.4 kwh/m2/year

This translates into approx. 60-65 kwh/m2/year in Primary energy ( energy at the source).
At the moment some 6000 passivhouses have been built in Germany as single family homes, row houses, schools, highschools, sport halls etc. So the Passivhaus concept is going mainstream. The passivhaus it not rocket science, but application of traditional materials in an optimal combination, coupled with good workmanship.  The important things are an airtight vapour barrier inside, trible glazed windows with insulated frames, ditto doors, 1-1½ feet insulation - floor-walls-roof and a ventilation with >85% heat recovery. The houses are tested with blower door for airtightness. Costs are +5-15% of ordinary buildings. The passive house principles can be applied to old buildings as well. Solar, PV etc can be added, off course and reduce energy consumption further.
regards/ And1