The first requirement of a passive house (right): very little heat leakage
Sweden went on a big building spree in the early 1970's as part of the Social Democrats' Million Program housing project. Much of the resulting buildings were just plain ugly - boxy and dull low- and medium-rise apartment buildings that tried to realize utilitarian ideals of the Swedish 'Folkhemmet' (loose translation: "the people's home") on a low budget.
Now much of this practical but visually sad architecture is in shabby shape, wiht an estimated 400,000 apartments needing help. In the southwestern town of Alingsås a typical 70's apartment complex called Brogården is about to receive not only a needed visual facelift but also a drastic energy diet. Eighteen of the 112 apartments in the Brogården development will be thoroughly renovated to meet passive building standards, cutting energy use from 216 kilowatt hours per square meter to around 92 kWh per m2. How will the re-developers do it?For the facelift the facade at Brogården will be replaced, as some of the bricks have frozen and buckled.
To meet the definitions of an energy-stingy passive house, the apartments must be newly (and much more thickly) insulated, equipped with more efficient appliances and lighting, and more energy-efficient windows and doors will be installed. New heat exchangers will use outgoing air to warm incoming air. The southern-facing rooftops will receive solar panels for water heating, though the wood-waste-based district heating will also provide warm water and heat back up.
The stick and carrot for renters at Brogården - after the renovation they will be switched from what is known in Sweden as "warm" rent - with all utilities included, to "cold" rent, where heat electricity, and water usage are individually paid, but also individually metered to encourage efficiency. Via ::PassivHusCentrum (mostly Swedish)