How much can be saved in Passive Houses? Save 70-90% of your heating costs and improve your indoor climate. The Passive House is the well-tested house of the future. Good insulation of up to 50 cm and an energy efficient ventilation system help prevent sleepless nights over rising energy prices. With minimum energy loss, free passive energy from sunlight, body heat and heat from appliances all help to make an important zerocost ‘radiator’. The energy savings more than compensate for the approximate 5%-15% extra investment. Compared to a standard new German house, a 120 m2 Passive House can – over a lifetime of 100 years – save approx. 660,000 kWh just for the heating alone. 5000 Passive Houses are already built So far more than 5000 Passive Houses have been built. A Passive House uses a maximum 15 kWh per sq.m. heated floor area – per year. Its annual consumption of primary energy for all energy use in the building (including appliances) must not exceed 120 kWh/m2. A modern house loses the thermal energy in three ways – through the building envelope (its walls, loft and foundation), through its windows and through ventilation – in particular through gaps and cracks. Low-energy buildings must tackle all 3 weak spots. With proper insulation, good windows, and gaps and leaks all sealed, the full benefit of a ventilation system with heat recovery is realised. Similar to a lung where ventilation must be controlled and accurate, rather than through leaks. Rockwool project The Rockwool Group is active in many projects to promote energy efficiency. In 2005 a price competitive lowenergy prefab house of high architectural quality was launched in Denmark. In Italy a Passive House, tailored for hot climates, is now under construction. And in Poland a Passive House competition for student architects is being run. Litre oil energy, consumed over 50 years, per m2 floor space in differently insulated buildings Sources: LCA data from Sverre Fossdahl, NBI, Energi og miljø regnskap for bygg Prosjektrapport 173 - 1995; EU, COM(2001) 226 fi nal 2001/0098 (COD), Bruxelles, 11 May 2001; Danish Energy Authority, Danmarks Energifremtider, 1995; Danish Building Code (Bygningsreglement 1995); Passivhausinstitut, Darmstadt, Germany; and Cepheus work group. This building from 1929 in Nürnberg was modernised and insulated with Passive House techniques. Energy for space heating shrunk 88% to just 25 kWh per sq.m. This is 3 times as energy efficient as most new buildings in Germany!