Australian Passive Solar Home

As you would expect, Australian government research agencies – notably the CSIRO – are experts in best building designs for Australia. Through the YourHome website and book, they give excellent advice about how to build for low energy consumption with thermal comfort.

Passivhaus – whose exponents claim it to be the best approach in the world for developing such housing – is barely mentioned. However, what is emphasised is passive solar design – eg using the sun to warm the house in winter. Regarding this, the site says:

“Effective [solar] passive heating has 5 main elements:

“Letting the sun in to your home – solar radiation travels through glass areas exposed to full sun.

“Storing the sun’s heat inside your home – trapped heat is absorbed and stored by materials with high thermal mass inside the home. This heat is released at night when the house starts to cool down.

“Ensuring good heat distribution – heat released from thermal mass is distributed to where it is needed through good design of air flow and convection.

“Ensuring that heat is not lost – appropriate house shape and room layout will reduce heat loss. Heat loss is […] minimised with appropriate choice of windows and curtains or blinds, and well-insulated walls, ceilings and floors.”

“Ensuring that cold air does not enter your home – infiltration of cold air is minimised with airlocks, draught sealing, airtight construction detailing and high-quality windows and doors.”

Incidentally, as the diagram shows, the entry of sun into the house in summer, when it’s not wanted, is prevented by mechanisms such as eaves.

It’s notable that Passivhaus does not use thermal mass in the above way. My guide to the Passivhaus software says in fact: “…thermal mass does not have a very significant effect on heating, cooling or comfort of Passivhaus buildings…”

Passivhaus is not passive solar design – it’s such a pity they hijacked the term.