We came across these wonderfully simple illustrations of the principles of Passive House design (Passive Haus) and thought they were well worth sharing. They are by a U.S. firm, Albert, Righter and Tittman Architects.
The illustrations help make the case that green building in the new millennium should be about simplicity: weaving together and maximizing simple technologies rather than relying on fancy gizmos and complex systems.
The first image shows the evolution in building technology over the centuries, from wood-heated homes in the 19th century, to a complex jumble of building systems in 20th century homes, to the promise of simplicity presented by today’s Passive House standard:
It’s all about the envelope. A central principle of Passive House design is to reduce heat loss by superinsulating homes, creating airtight building envelopes, and eliminating thermal bridges (elements or penetrations that allow heat or cold to leak through the fabric):
With a carefully-designed and executed building envelope in place, almost all the heating needs of a Passive House can be met by body heat, heat from lights and appliances, and solar gain:
The control of these solar gains can be easily regulated though a combination of well considered siting (along the east-west axis), shade-providing overhangs for the highest sun of the summer months, and the careful placement of high-performance windows. All that’s left is to include heat-recovering mechanical ventilation, a simple system that exhausts spent air and brings in fresh air, all the while capturing and retaining the thermal energy of that exhausted air:
The end result is a comfortable, normal-looking home that saves 75-90% of the energy consumed by a conventional home.
Hofler Architects - Monkstown, Dun Laoghaire, Co. Dublin