  We study Gauge-Higgs Unification in five dimensions on the lattice by means
of the mean-field expansion. We formulate it for the case of an SU(2) pure
gauge theory and orbifold boundary conditions along the extra dimension, which
explicitly break the gauge symmetry to U(1) on the boundaries. Our main result
is that the gauge boson mass computed from the static potential along
four-dimensional hyperplanes is nonzero implying spontaneous symmetry breaking.
This observation supports earlier data from Monte Carlo simulations [12].
