Is there a charge for secondary electromechanical design?

No charge. According to the decoration website, the hotel electromechanical design fee includes primary electromechanical design and secondary electromechanical design, which are included in the hotel design fee by the design company, so the secondary electromechanical design is free of charge. The secondary electromechanical design is consistent with the primary electromechanical design and is an extension of the primary electromechanical design.