Comparing prefab ADU costs vs custom-built ADUs. Pros, cons, and which option is right for your San Diego property.
When planning an ADU in San Diego, one of the biggest decisions is whether to go with a prefab (modular) ADU or a custom-built ADU.
Prefab ADU: $135,000-$250,000 Installed
Pros: Faster construction, predictable pricing, quality controlled environment.
Cons: Limited customization, delivery access issues, may look cookie-cutter.
Custom-Built ADU: $165,000-$350,000+
Pros: Complete design flexibility, matches your home, maximizes your lot, works on challenging sites.
Cons: Longer timeline, more variables, requires more decisions.
Which is Better?
Custom ADUs often command 10-15% higher rents due to better integration, higher quality, and optimized layouts. We specialize in custom-built ADUs because we believe they offer the best value.
Ready to Start Your Project?
Contact One Stop Builders for a free consultation.
