A building in Kaufbeuren, Germany, is the first to receive Passive House Premium certification. The House of Energy is one of the world’s most sustainable buildings. It has an annual heating demand of only 8 kWh / sq m (0.7 kWh / sq ft) and a 250 sq m (2,691 sq ft) photovoltaic system on the roof.

The new Passive House Premium building class was launched earlier this year, along with the Passive House Plus class. They have been developed to take into account the transition of building energy sources from fossil sources to renewable energy.

For Passive House Plus accreditation, a building must not consume more than 45 kWh / sq m (4.2 kWh / sq ft) of renewable primary energy a year and must generate at least 60 kWh / sq m (5.6 kWh / sq ft) of renewable energy a year. The stricter Passive House Premium parameters sees these figures fall to 30 kWh / sq m (2.8 kWh / sq ft) and rise to 120 kWh / sq m (11.1 kWh / sq ft), respectively.

The House of Energy actually falls slightly short of the required energy generation requirements at 103 kWh / sq m (9.6 kWh / sq ft) annually, but has still been awarded Premium accreditation due to excellent energy usage levels. Its overall demand for renewable primary energy is just 21 kWh / sq m (2 kWh / sq ft) per year, which is almost a third less than required, and thus has been allowed to compensate for slightly lower energy generation.

To achieve its Premium accreditation, the 900 sq m (9,688 sq ft) building uses a variety of technologies – none of which, it should be noted, are especially out of the ordinary today.

Energy efficiency is delivered through triple-glazed windows, an "excellent level" of thermal protection, a high level of building envelope airtightness, construction that us largely thermal bridge-free and a ventilation system with heat recovery. A number of different ventilation system were actually installed initially for comparison.

Elsewhere, a ground-source heat pump provides the small amount of additional heating and hot water that is required. Any surplus energy that is generated via the photovoltaic system, meanwhile, is fed back into the grid.

The House of Energy was completed last year. Its recently-awarded certification will be presented to the building owners over the International Passive House Days of Nov. 14th and 15th, when the building will also be open for public visits.

Sources: Passive House Institute, Passive House Database, Airoptima