What makes a design a solar passive extension rather than just a ‘normal’ extension is in the way the design is made to capture and store solar energy and share it with the building that it is an extension of.
We attempted to do this with this extension In the following ways:
It faces the sun and presents an insulated glazed wall in that direction.
- It closes down (ie makes as small as possible) windows facing in other directions.
- It uses solar shading in the form of a roof overhang to mitigate summer overheating.
- It is highly insulated, and its details avoid cold bridging.
- It uses materials of high thermal mass inside it’s insulated ‘jacket’. This in order to retain and hold heat – in particular solar-generated heat.
- It is open-planned to the existing living spaces on the ground floor of the house so that solar-generated heat can be shared with the existing house through natural diffusion.
- In hot summer weather the doors and rooflights of the extension can work in combination with windows elsewhere in the house to create cooling through droughts because it is open-planned to the existing accommodation.
- The high thermal mass inside assists cooling when it is shaded from the sun, because high thermal mass in shade acts to cool (think of the inside of an old stone church or cottage on a hot day).
An example of the rainscreen cladding to be used on the extension.