To solve this the data (configurations files for client build) and the tools for building a client installation package needs to be separated eg. the actually build of the client should be performed in directory where current user has write access probably the users APPDATA directory.
There are few questions to be solved here:
should configurations be per user of all users ?
is all users data writeable by a user ?
should a users need to "initialize" the build manually to copy template
configurations into current user appdata ?