The construction of the building isn't (normally) the Architect's responsibility - the General Contractor or Construction Manager has that role. However the Architect does have a role in seeing that what is built meets the documents that he/she has prepared, and that the Owner receives the building that he/she has paid for.
Continuing with the Architect's final tasks during construction...
Some projects don't have changes, but nearly all do. Humans are fallible. Owner's change their minds. Better ideas come to light. In each case the contract for the construction work needs to be amended by a Change Order. The Change Order states the amount of money for the change, a description of the work it encompasses, any change in project duration, and any background information like details, pricing, and so on. The dollar amount of the Change Order may increase or decrease the Contract Sum. Not surprisingly, increases outnumber decreases by about 20 to 1 in both quantity and amount of money. Owners do not like Change Orders. The Serene Architect avoids Change Orders.
The Punch List
See this article. When the project is nearly complete, a Punch List is prepared to determine any work needing correction. It is in everyone's interest to correct the work as it proceeds, and the Punch List isn't intended to be a list of what is left to be done. Some Owners want to be involved, most do not. Your engineering consultants should make their own reviews and lists. Once complete, the Punch List is given to the constructor to oversee completion of the items; and the Architect makes one or more re-visits to confirm that the work has been corrected acceptably. Getting subcontractors to return for an hour's worth of work is challenging. But the project can't be closed out until the Punch List is complete.
Certificate of Substantial Completion
An AIA form is often used to document this milestone, and many contracts require its documentation. Sometimes Substantial Completion is the trigger for retainage (money held back from pay requests) to be reduced or released. If the project is bonded, the constructor's surety must give consent to any change in the amount retained by the Owner. The main prerequisite for declaring that the project is substantially complete is having received a Certificate Of Occupancy from the authority having jurisdiction. The Certificate of Substantial Completion documents the constructor's and the Owner's agreement on when insurance will change hands, when responsibility for security will change over, what remains to be complete and by when, and the start date for warranty periods.
The process of closing out a project is the reason that the end of the Construction Administration Phase is blurry. You and the Owner want to receive a number of documents. The Owner still has to make the final payment to the constructor, and that is the only leverage for ever getting those documents. Here is a listing:
Because many warranties lapse after one year, it is a good idea to make a walk-through at about ten months after Substantial Completion. Some Owner-Architect agreements require it. If not, you might offer it as an additional service or look upon it as a marketing opportunity. Most things that are warranted are not items that you can check visibly. Often you will need to interview those who would know whether anything leaks, the AC works, hardware functions, etc. Having overseen the completion of these warranty items, the project is complete and the Construction Administration Phase ends.
Other articles in this series:
Construction Administration - Part 1
Construction Administration - Part 2