Jiu-Kang Yu has an article "Bruhat-Tits Theory and Buildings" which has appeared in "Ottawa Lectures on Admissible Representations of Reductive $p$-adic Groups". It doesn't directly address your question, instead it contains a guide to the literature on Bruhat-Tits buildings.
From memory there are two versions of this article. There is a 26 page pdf version of Yu's article. It is a long time since I saw theThe published version contains a bit more information, but if I remember correctly itnot a lot more (a few more references are added, plus a short introduction, plus the typesetting is quite different fromupdated). Unfortunately the pdf and very hardprinted version is hard to find.