Those who have answered this question before me have grasped the gyst of V.W.'s purpose perfectly, so it'd be redundant to harp on what has already been said. Still, there is still the factor of experimental writing in which she and some of her contemporaries were involved, and the extraordinary resource of highlighting the passing of time through the description of the house in Part II. It's thought-provoking that humans play practically no part in this section of the novel, and that the three deaths are mentioned in passing, as it were. To my mind, the symbolic meaning of the house decaying only to come back to life in anticipation of Part III is an amazing literary resource, considering the time when the novel was written. One last thing that I'd like to mention is the poetic quality of the prose, a feature very much her own, since other contemporary writers of the stream-of-consciousness (Joyce and Faulkner, for instance) did use language features in new ways, but did not seem to find the poetic element important to their constructs.