**4. Conclusions**

This article details the development process of a bio-inspired design tool called the thermo-bio-architectural framework (ThBA) for energy efficient building design. The ThBA was developed through conducting a comprehensive literature review on thermal adaptation-associated concepts in biology. These involved exploring different modes of bioheat transfer, thermal adaptation strategies and the thermal physiology of living organisms. Reviewing these, passive and active ways of thermoregulation linked to the concepts of endothermy and ectothermy emerged as the most appropriate for structuring the ThBA. Heat generation is the key to the concepts of endothermy and ectothermy and the fact that the heat source in nature is either inside or out of the body of organisms, meant there were exact parallels in energy efficient building design. Once created, the ThBA was used in a focus group where biology experts confirmed the inclusiveness, effectiveness and applicability of both the animal and plant parts of the ThBA [41]. This is the first time that a comprehensive framework has been developed to bridge the gap between biology

and architecture. The ThBA could assist architects in finding relevant biological thermal adaptation strategies based on the thermal needs of a building.

**Author Contributions:** N.I.: Data collection, Data analysis, Methodology, Visualization, Writing and Editing; B.V.: Writing, Reviewing and Editing. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Conflicts of Interest:** The authors declare no conflict of interest.
