  We investigate Bruhat-Tits buildings and their compactifications by means of
Berkovich analytic geometry over complete non-Archimedean fields. For every
reductive group G over a suitable non-Archimedean field k we define a map from
the Bruhat-Tits building B(G,k) to the Berkovich analytic space Gan asscociated
with G. Composing this map with the projection of G^an to its flag varieties,
we define a family of compactifications of B(G,k). This generalizes results by
Berkovich in the case of split groups. Moreover, we show that the boundary
strata of the compactified buildings are precisely the Bruhat-Tits buildings
associated with a certain class of parabolics. We also investigate the
stabilizers of boundary points and prove a mixed Bruhat decomposition theorem
for them.
