Planning Minister Peter Gutwein tabled new framework legislation for a statewide planning scheme late last month, which he says will raise planning consistency from 15 to 80 per cent between Tasmania's 29 councils.

The proposal, while strongly supported by industry and developer groups, has been received with hesitancy from the Greens and the Tasmanian Conservation Trust.

LGAT has since added its name to those with concerns, voicing opposition against a reduction in development application and assessment timeframes.

LGAT acting president and Circular Head mayor Daryl Quilliam said the association's view had been ignored by the state government.

"We are extremely disappointed that the government did not respond to our concerns regarding the reduction of assessment timeframes for permitted development applications," Cr Quilliam said.

"[They have] tabled an amendment to reduce the timeframe from 28 to 21 days, we will be lobbying against this."

He said the 28-day assessment allowed planning authorities to work with developers to address problems or deficiencies in applications, without having to issue a formal information request.

"Assessment timeframes in Tasmania are already significantly less than other states, and were recently reduced from 42 days to 28 days," Cr Quilliam said.

"The Tasmanian Planning Scheme is not yet widely understood and local government strongly feels there is a high risk in reducing timeframes before a new systems is implemented and tested."

Although the scheme's implementation has been heralded as a conduit for fast-tracked development approvals, Cr Quilliam said the association believed there was no evidence to support this.

"The Tasmanian planning scheme will identify more permitted pathways and introduce more consistency, but the process requirements remain the same," he said.

"In itself, it does not make things faster, nor necessarily simpler.

"The local government sector looks forward to broader consultation on the detail of the Tasmanian planning scheme."