The Government has launched a new independent Crown entity tasked with addressing New Zealand's "unprecedented infrastructure deficit".

The New Zealand Infrastructure Commission – Te Waihanga – would look at ways of fixing and further funding areas where infrastructure investment is needed.

Transport projects and urban infrastructure issues would likely be the focus of the new commission.

Infrastructure Minister Shane Jones said New Zealand has an "unprecedented infrastructure deficit" and the commission was tasked with addressing that.

He said New Zealand's transport and urban infrastructure was struggling to keep up with population growth.

"This infrastructure deficit is manifesting in housing unaffordability, congestion, poor-quality drinking water and lost productivity."

"That's simply not good enough," he said.

The Treasury has estimated the total infrastructure spend over the next five years would be $42 billion – more than double that of the past five years.

Jones said this showed why the establishment of the Infrastructure Commission was needed.

Overall strategy and planning would be the focus of the new body.

In a Cabinet paper, Jones said the Infrastructure Commission would also act as a "shop front" for private companies looking to invest in New Zealand.

He pointed the finger at the previous Government, accusing National of focusing on short-term projects and under-investing in infrastructure projects.

Local Government New Zealand president Dave Cull said unprecedented population growth and the need to adapt for climate change, as well as a low-emissions economy, means that New Zealand was "behind the eight ball in terms of infrastructure investment".

"Having a central agency to act as a shop front that the private sector can interact with, and having an ability to buy goods and services in bulk will be a massive benefit to regional development projects," he said.

The Cabinet has approved just over $4 million to establish the commission and legislation establishing the body would go before Parliament in April.

The creation of the Infrastructure Commission has been well flagged – in August last year Jones announced work had begun on establishing the body.

He said Treasury had been unable to properly quantify the value of the infrastructure deficit New Zealand was facing which he said "was not good enough".

The new body would work to quantify the level of the deficit, as well as figuring out how to fix it.

The Government received 130 submissions on what the body should look like.

"We have heard that message, and we have delivered."

Ministers will retain final decisions on infrastructure investments, but the Commission will have an independent board and the autonomy it needs to provide robust, impartial advice.

"It will help hold this Government, and future governments, to account and we welcome that," Jones said.