"The fact is we don't need Parliamentarians, 100 would be sufficient, at which time we would have plenty of room."
Peters said the public of New Zealand had voted to reduce the number of MPs to 99 in a referendum in 1999 but it was never acted on.
After New Zealand adopted MMP it went from 99 electorate MPs in 1993 to 120 electorate and list MPs.
NZ First believed numbers should be cut, given 81.5 per cent had supported the reduction in the referendum.
He said some ministers could also consider cutting the number of staff they had to free up space.
"Former Prime Minister Keith Holyoake used to have five people in his office - Prime Minister John Key has 55. Before anyone starts screaming about the need for more space let's take a look at how bloated the system now is."
Those staff numbers included the Prime Minister's Office as well as the Department of Prime Minister and Cabinet. Peters has eight full-time equivalent positions in the NZ First leader's office and three Northland electorate staff.
Peters said a National Government sold Bowen House in the 1990s and it was now paying the price.
"As usual the taxpayer is being hit hard by the decision of National to sell state assets."
Bowen House is home to a handful of ministers as an overflow from the Beehive, as well as the smaller parties - the Maori Party, Greens, Act, United Future and NZ First.
There are 121 MPs - United Future leader Peter Dunne is an electorate MP but its party vote was not enough to qualify for an MP, resulting in an overhang.