Pentan Partnership director John Carter has qualified as a certified Passivhaus designer - a Europe-wide, low-energy housing qualification, administered by Germany's Passivhaus Institute (PI). After an intensive PI-approved course, held at Glasgow's Strathclyde University, and subsequently passing the PI examination, John is now certified as a Passive House Designer. The Passivhaus principles of low-energy design, evolved by the Darmstadt-based PI in the early 1990s, mean that it is possible, with good siting, careful internal planning, high-levels of insulation, excellent air-tightness and efficent mechanical ventilation and heat recovery, to design and construct a house that uses only a fraction of the energy that a standard house consumes. As John says, "Passivhaus sets a standard that all new houses will need to achieve if we are to live within our planetary means. It takes common-sense principles and applies them rigorously, to achieve very low levels of energy consumption - and it works ! Unlike many other examples of low-energy housing, the Passivhaus theory is proven in practice, over many thousands of dwellings."