Successive governments had failed to confront the planning system which he said was to blame for the housing crisis, Seymour said.
"We simply don't allow enough building – whether up or out – to house our growing population. Governments of all stripes have failed to confront this challenge."
Seymour said the label "boomer" had been used as a term of derision "but that generation knew how to build houses".
Referring to Statistics New Zealand data, Seymour said New Zealand's population had grown by 2 million since the mid-1970s but "we're building fewer houses than we did then".
In fact that graph shows a peak of 40,025 new monthly house consents granted in February 1974 before a steep decline, then a steady rise and fall until July 2011 when consents bottomed out at 13,236.
They then rose again and in June this year there were 37,614.
Seymour said an entire generation had been locked out of home ownership with thousands living in insecure housing while others had no home at all.
Act joined Labour and National with their commitments to scrap and replace the RMA.
Act would replace it with the Environmental Protection and the Urban Development Acts.
National would replace the RMA with an Environmental Standards Act and a Planning and Development Act. While Labour a Natural and Built Environments Act and a Strategic Planning Act alongside further climate adaptation legislation.
The Green Party is calling for it to be reformed but with assurances it won't come at the expense of environmental concerns or public consultation.
Seymour said Act's plan would allow faster infrastructure development and ambitious projects "without living in fear of the Environment Court".
It would also promote more sensible land use regulations so more Kiwis could afford to live in cities, he said.
"If we allowed more New Zealanders to move to higher-wage cities and boost their personal productivity, we could increase overall income significantly. That one effect on its own could make New Zealanders significantly richer."
Act also wants compulsory 30-year building insurance from a company regulated by the Reserve Bank which would give homeowners assurance of receiving compensation is their home turned out to be poorly built or with shoddy materials.
That would have the knock-on effect of requiring council inspections which Seymour said would help homes be built more cheaply.
Seymour said Act also wants to see local councils be able to form 30-year infrastructure partnerships to enter into long-term contracts with the central government, for example Auckland, the Bay of Plenty, and Waikato could form a golden triangle partnership.
Those partnerships would then be able to get funding from the government, private sector or overseas investors, which would be allowed through their plan to reform the Overseas Investment Act.
"At the heart of the problem is a separation between planning, which is done at a local level, and infrastructure funding, where central government has the overwhelming majority of revenue," said Seymour.
"Central government can afford, but can't plan, infrastructure, and local government can plan, but has little revenue.
"Governments have chosen where to build roads, bridges, and railway lines, based on political advantage rather than economic need, and changes of government every three years bring uncertainty and the risk that decisions will be reversed."