ADU Costs Range $150K to $350K in 2025
Discover the real 2025 costs of building an Accessory Dwelling Unit—from garage conversions to detached backyard cottages. Learn average prices, major cost drivers, and smart savings strategies. Explore financing, ROI potential, and pro versus DIY options to plan an ADU that maximizes space, value, and long-term financial return.
By Rod Kerby
4 min read