ADU Costs has priced out the New Construction Costs for an Accessory Dwelling Unit (ADU). These prices can range anywhere from $146,500 to $416,500 for the average homeowner. In contrast, converting a single-car garage into an ADU typically costs less, with the total cost typically between $99,750 and $138,750. These estimates include the full range of costs, from design and … Continue reading The Breakdown of ADU Costs for 2025