Accessory Dwelling Units (ADUs)—also known as in-law suites, granny flats, or backyard cottages—are transforming how families live, age, and thrive together. Create a second home under your own roof—whether for family, income, or independence. This comprehensive guide shows you how to turn one house into two homes with smart design, practical planning, and real-life inspiration. From attic and basement conversions to garage makeovers and backyard builds, this book explores every type of second-unit solution.