| Passive solar | Passive House |
|---|---|
| Specific insolation requirements, right orientation is paramount | Works with minimal solar gains (e.g. southern orientation) |
| Additional thermal mass requirements | Does not need additional thermal mass |
| Needs favourable weather conditions to be comfortable | Is comfortable year round |
| Provides desired solar gains predominantly during spring and fall | No heating requirements during spring and fall |
| Relies on natural forces for ventilation | Uses controlled mechanical ventilation |
| Design principles are widely promoted | Clearly defined and proven concept |
There is always a tad confusion when I talk about Passive Houses. Passive Houses and passive solar concepts are not the same thing. I have highlighted the most prominent differences above. Both concepts attempt to make use of free energy, with the aim of reducing the depletion of fossil fuels - yet the means of getting there differ.