ADU Cost in Southern California: 2 Real Projects (2026)

How much does it cost to build an ADU in Southern California in 2026? In this video, we compare 2 completed L Square ADU projects: • Pasadena: 700 sq ft, 1 bedroom, 1 bathroom — $220,000 total, approximately $314 per sq ft. • Rosemead: 1,188 sq ft, 2 stories, 3 bedrooms, 2 bathrooms, a loft and balcony — approximately $280 per sq ft. The larger ADU had a lower cost per square foot. We explain why ADU size alone cannot determine the final construction price. You’ll learn how site access, sewer and utility distance, electrical-panel capacity, soil conditions, foundation requirements, design complexity and finish selections can change an ADU budget. These completed projects are real examples, not universal price quotes. Every property has different access, utilities, city requirements and site conditions. L Square Design & Build provides ADU design, permit and construction services throughout Los Angeles County and Orange County. View our completed ADU projects: https://lscontractor.com/projects/ Request a property-specific ADU consultation: https://lscontractor.com/contact/ Website: https://lscontractor.com/ L Square Design & Build California Licensed General Contractor CSLB #1095476 Phone: (949) 374-7980 #ADUCost #CaliforniaADU #SouthernCaliforniaADU