What is Passive Design?
How orientation, mass, shading and ventilation can do most of the work, before any mechanical system is even switched on.
Passive design is the practice of shaping a building so it stays comfortable using the climate itself, sun, shade, wind, mass and vegetation, rather than relying on mechanical heating and cooling.
The core levers are orientation, openings, thermal mass, insulation, shading and natural ventilation. When these are tuned to the local climate, heating and cooling loads can drop by 40–70% compared to a conventionally designed building of the same size.
In a Mediterranean context, the priority is keeping summer heat out: deep overhangs and external shading on south and west façades, cross-ventilation aligned with prevailing breezes, high thermal mass on protected interior surfaces, and night-flush cooling. Winter performance follows from a well-insulated, airtight envelope that captures low-angle southern sun.
Done well, passive design is invisible: the building simply feels right, and the mechanical systems become a quiet supporting layer rather than the main character.