Is it valid for Chongqing first-class builders not to sign by hand?

Invalid.

A first-class builder is a professional qualification in the construction industry and a necessary condition for being a large-scale project manager. Construction engineer refers to the registered personnel engaged in key positions of general contracting and construction management of construction projects. Construction engineer is a compound talent who knows management, technology, economy, laws and regulations, and has a high comprehensive quality. He should not only have a theoretical level, but also have rich practical experience and strong organizational ability.