A number of innovations in building envelope technologies have been implemented recently, for example to improve insulation and air tightness to reduce energy consumption. However, growing concern over the embodied energy and carbon as well as resource depletion, is beginning to impact on the design and implementation of existing and novel building envelope technologies. Biomimicry is proposed as one approach to create buildings which are resilient to a changing climate, embedded in wider ecological systems, energy efficient and waste free. However, the diversity of form and function in biological organisms and therefore potential applications for biomimicry, requires a holistic approach spanning biology, materials science and architecture. It is considered timely to re-examine opportunities to learn from nature, including in the light of recent understanding of how plant form and function are determined at the cellular levels. In this paper, we call for a systemic approach for the development of innovative biological and living building envelopes. Plant cell walls are compared to building envelopes. Key features of cell walls with the potential to inform the development of design principles of biological and living building envelopes are identified and discussed.