Professor Christian Nygaard of UNSW's City Futures Research Centre argues that even an ambitious overbuild of 1.2 million homes over five years, and sustained for 15 more, would only marginally improve Australia's housing affordability. His modeling suggests this Herculean construction effort might reduce the national house-price-to-income ratio from 8.0 to 6.7, and in Sydney from 12 to 10. Nygaard explains this limited impact is due to rising incomes, increased demand fueled by tax settings and borrowing costs, and the fact that supply increases often lag household growth. He emphasizes that focusing solely on building numbers overlooks crucial factors like the distribution of new housing and the influence of tax policies, particularly capital gains tax on owner-occupied homes, which he believes are politically difficult but necessary to address.