From Wikipedia: “The Houses of Iszm is a science fiction novella by Jack Vance, which appeared in Startling Stories magazine in 1954. It was reissued in book form in 1964 as part of an Ace Double novel, together with Vance’s Son of the Tree . The story published in Startling Stories is about 22,000 words while the version that appears in the Ace Double still less than novel length at about 30,000 words. The Houses of Iszm was re-published as a stand-alone volume in 1974 by Mayflower. ” (more on Wikipedia)
Republished by Spatterlight in 2012.