From Retrofitting to Adaptive Fitting: Time Scale and Locus of Change Capacity in Adaptive and Demountable Building Envelopes

Building envelopes are addressed by two largely separate bodies of research: adaptive façade design, which treats change as behaviour during operation, and design for disassembly, which treats it as an end-of-life property. This study asks whether that separation reflects a division in the problem or in academic labour. Four modes of intervention through which envelopes are kept fit (add-on, replace, cover it, and wrap it) are mapped onto four fitting modes of natural skin; the correspondence weakens as the intervention becomes more external. Fifteen documented cases are then coded against a scheme separating the time scale at which change is accommodated from the location and type of the capacity accommodating it, with predictions recorded before coding. Every biomimetic case operates at daily or seasonal scale, and fourteen of fifteen cases return a functioning envelope when their adaptive capacity is removed. Cases addressing life-cycle change do so through external agency, and none has undergone the change it anticipates. No case addresses the intermediate scale of years to decades, at which buildings in fact become unfit. The unoccupied combination is termed adaptive fitting here, and the argument advanced is that the obstacle is evaluation before capability: envelopes are assessed on how they behave, not on how long they continue to behave that way.