Australians might have to wait a little bit longer for the opening of applications for the federal government's HomeBuilder scheme.

After almost a month since the announcement, the HomeBuilder scheme has, so far, garnered the support of only four states: South Australia, Tasmania, Northern Territory, and Western Australia. These states have already signed the HomeBuilder National Partnership.

The HomeBuilder grant aims to provide $25,000 in assistance to eligible Australians who are planning to construct a new home or renovate their existing property. Existing state and territory mechanisms will be used to distribute HomeBuilder payments.

The state and territory governments are slated to process applications for the scheme until the end of the year. However, there are no updates yet about the commencement of applications.

The federal government recently announced three key refinements to the scheme. The grant now provides the necessary time for homebuyers to arrange their finance approvals, building approvals and meet other legal requirements before work is required to commence. It was initially announced that the scheme would work on a fixed three-month timeframe.

"Recognising that a fixed three-month timeframe to commence building work did not reflect how dependent home builders are on other players, like the banks, the councils and building certifiers, is extremely important and a welcome update," said Kristin Brookfield, chief executive for industry policy at the Housing Industry Association.

It was also clarified that a sales contract for a home purchased off-the-plan will be eligible in the same way as a building contract.

A spokesperson for Queensland Treasurer Cameron Dick said there are still concerns about the implementation of the scheme that needed ironing out.

"The Queensland government supports the intent of the policy and is seeking to resolve the remaining issues around administration. We're continuing to work with the federal government to resolve those matters as quickly as possible," the spokesperson told ABC News.