Have a look at this Data Center Site Planning Guide from Sun. It covers many important aspects that need to be taken into consideration when planning a data center.
As an IT PM myself, who also knows about data centers, the answer depends on the experience and skills of a construction PM. I have never had the pleasure of working with construction firms that really “know” data centers, even if they have built a few in their day.
For example – The construction PM knows about electrical systems and would know the codes to follow. They thus would make sure things like ground fault interrupts and power distribution units were in place and sized appropriately. However, there is a set of business requirements that deals with meeting data center service level agreements (SLA’s). If an IT PM knew the organization was expecting to achieve a 99.9% data center availability objective, they would then know that certain measures need to be taken during electrical construction, which may include the selection of and installation of redundant UPS systems and backup generators.
I think this is in general what the experience of an IT PM would bring to the table, being able to translate IT centric requirements into right-sized and appropriate environmental infrastructure that would achieve the requirement’s objectives.