On average, a prefab home costs between $80 and $120 per square foot. On the low-end, you can build a very basic 1,600 sq.ft. prefab home for $128,000-192,000. Mid-range prices for a 1,800 sq.ft. prefab house range from $144,000-216,000, and 2,000 sq.ft.+ higher – end prefab homes start at $160,00-240,000+… Read more »