An Intro to Solar Passive Design

If you’re interested in sustainable building, you may have seen the term “solar passive design” thrown around describing certain aspects of a design. But how does it work?

Solar passive design is the principle of capturing as much sunlight (solar radiation) as possible, along with the heat energy that comes with it, to naturally warm a space in the cooler months of the year – relying less on mechanical heating & energy consumption. In Australia, this is done by placing large windows in the north-facing walls of a building, since the sun travels on a lower path through the northern sky during winter. (In the Northern Hemisphere, the important windows face south.)

This approach is often paired with a heavy material mass on the opposite side of a room, like masonry walls or exposed concrete flooring, which are then slowly heated throughout the day by the sun, and then radiate that heat back into the space through the night, ensuring a naturally more balanced, comfortable living space for the inhabitants.

In summer, the opposite approach is taken – we want as little sunlight as possible to enter the living space of a house. Since the sun sits higher in the sky during summer, this can usually be achieved by making sure the roof eaves overhang our northern windows enough to shade the whole floorspace. This doesn’t stop diffused solar radiation penetrating the house though – so often roller shutters, block-out blinds or temporary shading can be used to keep the house naturally cooler in the summer months. The heavy material mass helps here too – it takes much longer to warm up and can keep spaces cooler for longer.

Solar passive design is just one important aspect we incorporate in our projects to create energy efficient, sustainable spaces. Talk to us to learn more!