Deciding whether an arbitrary graph contains a sun was recently shown to be
NP-complete. We show that whether a building-free graph contains a sun can be
decided in O(min$\{m{n^3}, m^{1.5}n^2\}$) time and, if a sun exists, it can be
found in the same time bound. The class of building-free graphs contains many
interesting classes of perfect graphs such as Meyniel graphs which, in turn,
contains classes such as hhd-free graphs, i-triangulated graphs, and parity
graphs. Moreover, there are imperfect graphs that are building-free.