This project provides a complete plumbing system upgrade for the existing two-story, 16-unit apartment building located at 11735 Courtleigh Drive, Los Angeles, CA. The scope includes the addition of new washers in six residential units, requiring expanded water supply lines, increased drainage capacity, new cleanouts, and revised venting systems. The Plumbing Site Plan details all code-required general notes, material specifications, and updated building demand calculations. The schedules show the entire building’s water supply fixture units (329.5 WSFU total) and drainage fixture units (286 DFU total), confirming the need to upsize the water meter to 2 inches and install a new 5-inch main sewer line to meet flow and pressure requirements. The design fully complies with the 2022 California Plumbing Code, including backflow prevention, vent termination rules, clean-out placement, and pipe insulation mandates.

The plan set also includes complete first- and second-floor water supply layouts and first- and second-floor waste/vent plans showing new hot/cold water lines, washer connections, air vents, and 2% minimum drainage slopes. Each unit features a dedicated fixture unit schedule to verify correct pipe sizing and pressure distribution. The isometric diagrams provide three-dimensional pipe routing for both water and waste systems, including coordination points between floors and vertical risers. The roof plan clarifies vent-through-roof (VTR) locations, while the final sheet includes plumbing details such as the Oatey washer supply box and vent-through-roof assembly, with notes highlighting missing standard details still required for permitting. Together, these drawings form a comprehensive plumbing upgrade package, ensuring the building meets current code, supports new washer installations, and improves overall system functionality and safety.