I think there is a word that exists, though it won't quite come to me, that describes the life of someone who purposely leads a sparse existence, materialistically, and has few, if any, possessions. The only word that comes to me is "monastic," but that's not quite right, and I'm thinking there exists a word that doesn't have any religious connotations. The right word could possibly, but not necessarily, indicate a nomadic quality, as well, or, at least, the quality of not being tied down to a particular location or domicile.
Example sentence:
Living in an easily-collapsed geodesic dome, and owning only a laptop, futon, table and a few sets of clothes, Ms. Hilgers' [single-word] lifestyle was envied by some and perplexing to others.