The term INSTANT HOUSE is a combination of two crossword solutions: PREFAB (6 letters) and HOUSE (5 letters). The term INSTANT HOUSE refers to a type of building that is constructed off-site in a factory and then transported to its final location. This type of construction is often used for residential homes, commercial buildings, and other structures. It is a quick and efficient way to build a structure, as the components are already pre-made and ready to be assembled.