The cones of pines  hygroscopic form-changing abilities, which are evoked by anisotropic behavior of the wood fibers. The cones open and close themselves as a reaction to the environmental conditions of “humidity” and “aridity” and as a result release their seeds.

This mechanism can be replicated to produce low-tech low-cost hygromorphic (moisture-sensitive) materials with the response driven by shrinkage and swelling wood.

Considering the requirements of ventilation, sunshine and privacy,We have chosen the appropriate cell size.

This effect is reinforced when the air can escape at the top of the cavity and is replaced by air flowing in at the bottom. Objects with suitable shapes can exploit the available incident air flows around a building to generate an additional negative pressure and therefore reinforce the stack effect, or even to accelerate the dissipation of hot air from rooms at a lower level.

We tested various materials to obtain different effects.


M07 Proactive Envelopes is a project of IaaC, Institute for Advanced Architecture of Catalonia, developed at Masters in Advanced Ecological Buildings in 2019/2020 by:

Students: Yue Zhang , Zhi qian Liu

Faculty: Miquel Rodriguez