  In dimension 3 and above, Bredon cohomology gives an acurate purely algebraic
description of the minimal dimension of the classifying space for actions of a
group with stabilisers in any given family of subgroups. For some Coxeter
groups and the family of virtually cyclic subgroups we show that the Bredon
cohomological dimension is 2 while the Bredon geometric dimension is 3.
