The first surprise
After the construction bid was released the phone system manager informed you that they were planning to deploy voice over IP (VOIP) for all voice communications. You mumbled under your breath as your original electronics estimate was for non-Power over Ethernet (PoE) switches. You resubmitted your cost estimates, now 22 percent higher.
The bid was awarded and construction began. After the frame of the building was completed, you toured the site with the fiber cabling contractor. You both noticed there were no conduits from the new building's MDF to the outside. While the cabling contractor had included in the estimate costs for installing four buried conduits to the building, building penetration was not included. Without this, the fiber-optic cable could not be pulled into the building.
The cabling contractor, like you, assumed it was the architect's responsibility for planning all pathways into the building. The hospital facilities manager assumed it was your responsibility because the network group handled the external conduit system. The general contractor insisted they were only required to run pathways and cable inside the building, per the bid documents.
The cabling contractor's fix was to core drill through the new foundation, at a significant cost. Midway into the project, the costs for data network connectivity had exceeded your original estimate by 35 percent.