  Volume stabilization in models with flat extra dimension could follow from
vacuum energy residing in the bulk when translational invariance is
spontaneously broken. We study a simple toy model that exemplifies this
mechanism which considers a massive scalar field with non trivial boundary
conditions at the end points of the compact space, and includes contributions
from brane and bulk cosmological constants. We perform our analysis in the
conformal frame where the radion field, associated with volume variations, is
defined, and present a general strategy for building stabilization potentials
out of those ingredients. We also provide working examples for the interval and
the $T^n/Z_2$ orbifold configuration.
