The building code on Mr. Keir's island guards explicitly against extremes of non-redundancy which can lead to danger of "disproportionate collapse" where disastrous results stem from the failure of a single structural component. An architect of my acquaintance keeps a clipping from the Times of London on his desk depicting a lady who closed the front door of her medieval house a bit too emphatically, so that when the dust cleared afterward, said door was the only part of the building left standing.
To give equal time to gravity and stability, readers may also want to consider Mr. Salvadori's Why buildings Stand Up, Norton, 1994, ISBN: 0393306763, and its English cousin, Structures : Or, Why Things Don't Fall Down by J. E. Gordon, Da Capo, 1988, ISBN: 0306801515.
This writer is reminded of a seminar at a past Quality Building Conference where a Boston rehabber rose to speak in praise of redundancy in old townhouses, since when know nothing new residents did stuff like cut out attic collar beams that were in their way, the buildings continued to stand, a feature whose absence in future highly optimized construction might prove fatal to such careless inhabitants. To which the engineer on the panel (not the guy you're thinking of) replied "People who do that deserve to die." An unusual sentiment, I thought, for one whose professional charge is public safety.
