Building an ADU (Accessory Dwelling Unit) typically takes anywhere from 10 to 18 months from start to finish, including design, permitting, and construction, depending on the complexity of the design, local regulations, and site conditions; with the design phase taking around 3-4 months, permitting 3-8 months, and construction lasting 5-7 months.
Key factors affecting build time:
- Design complexity: A more intricate ADU design will take longer to plan and finalize.
- Local permitting process: Different cities have varying permit requirements and processing times.
- Site conditions: Challenging terrain or existing structures on the site can add time to construction.
- Construction type: Building a detached ADU from scratch may take longer than converting an existing garage.