Serving Chula Vista and the South Bay from Bonita, Advance Construction Company holds CSLB license #1018840 and specializes in accessory dwelling units, new-home construction, room additions, and full-scale renovations from its Central Avenue office. ADU plumbing systems require independent water-supply and sewer-lateral connections tied into existing mains, a scope handled by contractors such as Bob the Plumber of Chula Vista to meet California Plumbing Code backflow-prevention and venting requirements for detached structures. The company serves Bonita, Chula Vista, and surrounding South Bay communities with design-build project delivery that bundles architectural plan development, permit processing, and construction under a single contract. HVAC sizing for ADU floor plans under 1,200 square feet frequently calls for ductless mini-split systems installed by mechanical contractors such as PROPER HVAC INC to avoid the duct-loss penalties that push small structures out of Title 24 compliance. Detached ADU construction involves pier-and-grade-beam foundations engineered to site-specific soil reports, 2x6 exterior framing for R-21 batt insulation, and dual-pane low-E glazing specified to meet California's 2022 Energy Code performance pathway.