Seems to be a contradiction between this:
The Defence Department – part of and paid for out of the common wealth – occupying land owned as common wealth and using facilities that were built at the cost of the common wealth – was now liable for around $1 billion in rent and aircraft landing and parking charges over the remaining life of a lease, for which the lessee will pay the common wealth $65 million.
And this:
Excluding premises constructed, or caused to be constructed, by the above at Defence Establishment Fairbairn.
To clarify it in my mind, does "by the above" mean Defence or Canberra Airport P/L?