The East and West portal buildings for the VTA's BART Silicon Valley Phase II Extension mark the entry and exit points of the 5-mile underground single-bore tunnel. NBA provided HVAC system design for above and below-ground ancillary rooms based on current municipal and California Codes. We provided calculations for cooling capacity size to meet CEC Section 6 Title 24. We provided ventilation and air conditioning system including exhaust for electrical, UPS, and Battery rooms, etc. NBA provided design plans and specifications per BART Design Criteria for mechanical systems. Additionally, NBA provided plumbing design for sewer, sanitary, wet well, dry well pump station, and roof drain that meets the California Plumbing Code. We provided plumbing calculations for sump pumps, roof drains, and plumbing fixtures if any. We provided calculations for submersible pumps for Wet Well and Dry Well Pump rooms. NBA provided plumbing drawings including plans, sections, riser diagrams, etc. and specs per BART design criteria and Title 24 forms for East and West portals.