It's Not a Passivhaus, It's a Plusenergihus
The passive house idea is so sensible, where instead of covering your house in green gizmos that generate heat and power, you design the systems so you don't need them. So Passiv Haus designs have very thick walls, lots of south facing windows and are boxy to reduce jogs that cause heat loss. But it does put some limitations on design, and makes some people nervous- will there be enough heat?
That appears to be the reasoning behind the Plusenergihus. It is like a Passivhaus with an extra kick from solar collectors and a stove.
Karin Adalbart is building the house in Åkarp, outside Malmö. According to the Google translation from Swedish,
Like passive houses so built her house very well insulated, fully dense and with heat in the ventilation system. The difference is that she chooses to install a traditional radiator system, where the water is heated by solar collectors and stove. My living room, next to fire the heater will be a great accumulator tank built behind plaster plates that will house the energy the heart, where the stored heat from solar collectors and the stove.
Meaning, I think, that the big round thing in the middle of the house is a storage tank for hot water collected from the solar panels.
More at Ecoprofile
More on Passivhaus in TreeHugger:
Passivhaus in the New York Times :
Solar Village by Rolf Disch
BaleHaus: It's Not a House, It's A "Domestic Carbon Bank"
Denmark Debuts First Certified Passive House
A Passiv Haus in Urbana, Illinois