I will electrical, hvac, plb system

Input Receipt & Design Standards BD Phase: Receive the Design Brief/Terms of Reference (TOR), planning boundary lines, and information on off-site infrastructure connection points (power supply, water supply/drainage); define the framework of applicable standards and regulations (QCVN, TCVN, IEC, NFPA, etc.). DD Phase: Receive approved BD documentation; update detailed architectural and structural layouts; gather technical documentation and equipment catalogs from potential manufacturers/suppliers. CD Phase: Receive verified/appraised DD documentation; receive catalogs for actual winning equipment; update architectural and interior layouts regarding actual ceiling, floor, and wall finishes. 2. Technical Calculations & Solution Selection BD Phase: Perform preliminary total load calculations (total electrical power, water supply/drainage flow rates, HVAC cooling capacity, fire-fighting water flow); select primary source options (transformers, backup generators, VRV/Chiller systems, underground water tanks). DD Phase: Perform detailed calculations for individual load branches: voltage drop, short-circuit current, cable cross-section selection, switchgear rating selection (ACB/MCCB/MCB