Architectural space of the 21st century confirms, for the umpteenth time that, architecture is a personified image of society: The products of architectural interventions are the final creations in time and space. The whims of the market, the linear economy model, and users' pluralistic needs generated by cultural preferences mutually develop "white elephants" - inert material, useless and expensive to deconstruct. In response to social, environmental, climate, and economic changes, the construction sector needs to revalue existing construction techniques. The lack of broader application of the circular economy model, the use of inorganic materials and chemical bonds in architectural structures, due to the loss of cultural significance or the appearance of natural disasters, are deprived of their function and produce a large amount of waste. Therefore, the reuse of organic materials derived from renewable energy sources is becoming essential for pushing further the boundaries of reversible design and energy efficiency in architectural interventions. Limits of use of the old – new materials - compressed straw are defined by comparing the results of thermal properties of the building envelope elements - U and R values and levels of reversibility through two opposite approaches to construction, on the example of the conceptual design of a housing unit affected by natural disasters. Analysing the three levels of reversibility that 21st century buildings should possess, given the existing research, the material level limit is shifted in terms of returning to nature with potentially zero environmental waste. Comparing the results of the R values of prefabricated straw structures with the R values of materials predominantly used in architectural interventions raises awareness of the importance and benefits of using compressed straw in architectural envelopes. Existing design parameters of straw structures are optimized by valorising the importance of local climate and materials used. The interaction of native - cellulosic materials breaks down dogmas related to this material and generates the architectural language of reversible and energy-efficient architectural straw products.