Cairns said given the long lead times for big infrastructure projects, there was a risk that only some of the planned initiatives would be able to take advantage of the legislation before it self-terminated in July 2022.
Extending the deadline would ensure more projects would be completed, Cairns said.
The report also found that more money would be needed in the longer term to fund infrastructure projects.
It suggested letting the infrastructure model levy to be adopted by a range of public agencies, not just local authorities.
"One other thing that we talk about is the idea of... introducing value capture financing techniques into New Zealand, these are things that are used abroad in other jurisdictions."
Cairns said the model worked by taxing properties whose values increased as a result of new infrastructure projects being built nearby, such as a new light rail system.
He said the tax would only apply to the capital gains the property realised after the infrastructure project was completed.
Among other measures, the report said the next-government should prioritise include RMA reform and show meaningful engagement on the three waters review.