The house is a 1 level building that can be entered to loot some chems, ammunition, a Patriot's Cookbook and other items that can found around inside the house. There is also a bed that can be used for sleeping. Usually 2 Fiends live in the house, 1 outside and 1 inside. There is also some vegetation growing around outside the house that can be harvested.
The Fiend house appears only in Fallout: New Vegas.