Since the first discovery of switchable MOFs in 2001, the number of new MOFs showing pronounced flexibility, huge changes in pore size and unexpected phenomena is increasing exponentially. Significant progress in understanding of the structural switching mechanisms was achieved by developing targeted in situ characterization techniques to assess local and global structural features. The thermodynamics of switching transitions can nowadays be monitored by in situ calorimetric methods supported by in silico simulations predicting free energies of frameworks and host-guest interaction. In particular, the adaptive deformation of mono- and multinuclear metal complexes poses tremendous chances for the deliberate design of switchable porous solids. Coordinative bonds act here as bistable hinges and the bond strength and associated deformability can rationally tune the framework switchability. At the same time, the connectivity of the multinuclear complex (node) plays a key role for the network topology, a second factor decisive for network switchability. In this sense, coordination chemistry acts as an enabler for a rational design of switchable frameworks. However, predictive simulation methods are still limited in terms of energetic precision due to the multiple subtle interactions involved, such as dispersive, dipolar and H-bonding interactions between organic linker moieties and their functional groups. But also the geometric changes of metal nodes are difficult to simulate in particular if abrupt changes of the spin state are involved (i.e. low-spin high-spin transitions). Moreover, cooperative phenomena, crystal size effects and the role of defects and disorder are poorly understood, and require further in depth analysis using advanced analytic....