its called a Re-establishment Survey and is done by a land surveyor.
The purpose of a re-establishment survey is to see where the fence sits compares to the title dimension.
You will not find it on the builders contract unless you agreed earlier.
Depending on how new the subdivision is, it may be that the pegs are in the ground and it is a simple matter of walking the block to find them.
These are the square pegs that are driven into the ground to signify where your boundary is. If these have been newly mapped out (i.e. a new subdivision) then they should be in place and easy to find.
Perhaps your builder is asking, simply because they haven’t been onsite yet, thus they don’t know if pegs are in place. If they are, tell him so – he might want you to draw up a rough map for him. No harm in asking, eh? Don’t pay $750 without checking with others first….