We've seen the Passive House sustainability marque awarded to plenty of big flashy home builds. A project in Australia, however, has shown that a certified Passive House needn't be either of those things. Castlemaine Passivhaus is covers just 39 sq m (419 sq ft) and took only 10 days to build.

Passive House certification is awarded to houses that demonstrate highly efficient energy performance. The standard focuses in particular on a building's heating and cooling system, air tightness and approach to ventilation. Not only does certification provide affirmation of a building's sustainability credentials, but large buildings in particular can benefit from the operational cost savings of measures taken to achieve certification.

Designed by Australian architects Carbonlite, Castlemaine Passivhaus shows the Passive House marque is not just reserved for large expensive homes. Carbonlite, which specializes in creating sustainable prefab homes, prefabricated the building's sections off-site over the course of about five days.

The sections were delivered to the site and on the same day the exterior was erected and the building made wind and watertight. The remainder of the house was fitted out over the course of the next 10 days, after which the it was possible for the residents to move in.