Newer infrastructure from the 1980s–90s makes utility hookups simpler and more affordable, strong rental demand from young professionals and tech workers, proximity to Laguna Beach and Irvine Spectrum, planned community amenities that attract quality tenants, and smaller lot sizes that still accommodate well-designed compact ADUs.
Aliso Viejo is one of California's newest incorporated cities, having become a municipality in 2001 after decades as a master-planned community developed by Mission Viejo Company. With approximately 51,000 residents, the city is characterized by its meticulously planned layout featuring newer infrastructure, underground utilities, and well-maintained common areas. The Aliso Viejo Town Center anchors the commercial district with restaurants, retail, and a movie theater, while Pacific Park — a 14-acre community sports complex — provides recreation for families. The city's housing stock was built primarily in the 1980s and 1990s, meaning electrical panels, sewer lines, and water mains are relatively modern compared to older Orange County cities — a significant advantage when connecting ADU utilities. Aliso Viejo sits along the Aliso Creek corridor with quick access to the SR-73 toll road and I-5 freeway, placing residents within 15 minutes of Laguna Beach, 10 minutes of Irvine Spectrum, and 20 minutes of John Wayne Airport. Major employers include Quest Software (now Dell), UST Global, and the retail and dining establishments along Town Center Drive.
Confirm your property's zoning on the city's GIS map. Most single-family residential zones allow ADUs by right. Contact the Aliso Viejo Community Association or your sub-HOA to request ADU architectural guidelines — they can require design review but cannot deny a compliant ADU.
Create architectural plans including site plan, floor plan, elevations, structural, mechanical, electrical, and plumbing. Aliso Viejo's smaller lots (4,000–6,000 sqft) call for efficient designs — consider a compact 500–750 sqft studio or 1-bed unit that maximizes usable outdoor space. Two-story designs can increase square footage without consuming limited yard area.
Submit your complete plan set to the Community Development Department. Include Title 24 energy compliance documentation. Aliso Viejo processes ADU applications ministerially — no public hearing or discretionary review is required.
The city reviews plans for compliance with building codes and ADU regulations. State law mandates a 60-day maximum review period for compliant ADU applications. If your HOA requires concurrent review, submit to both simultaneously to avoid delays.
Once permitted, begin construction with your licensed contractor. Schedule required inspections at each milestone — foundation, framing, rough mechanical/electrical/plumbing, insulation, and final. Aliso Viejo's newer infrastructure means utility connections (sewer, water, electrical) are typically straightforward with fewer surprises than older cities.
Request final inspection from the Building Division. Once passed, receive your Certificate of Occupancy. Your ADU is now legal to rent or occupy.