Hundreds of people have packed into a forum at Hobart Town Hall to voice their opposition to the Tasmanian Government's proposal to change planning laws.

The State Government intends to create a statewide system that replaces 29 different council schemes which deal with development applications.

At the forum, Building and Construction Minister Guy Barnett said the proposed changes were sensible and would invite investment to Tasmania.

"It'll create certainty for developers, it'll create an opportunity for further investment that'll bring on more development and growth and jobs, and this is the sort of outcome we want in Tasmania," he said.

But the majority of people who filled the Town Hall objected to the changes.

Greens MP Rosalie Woodruff said they were more about luring investment than proper process.

"Under the pretence of uniformity and under the pretence of cutting red tape, it's actually about smoothing the way for development — it's about getting rid of difference, the beauty that is Tasmania," she said.

"The problem with the planning scheme is it gives the Minister power to sign off anything the Minister wants to."

The changes could also mean major development projects, like a 120-metre tall hotel at 28-30 Davey Street in Hobart's CBD, could fall to ministerial discretion.

Last month, Singapore-based company Fragrance Group unveiled its plan for the 35-storey five-star hotel.

It is being considered by the Hobart City Council (HCC), but if it were rejected the developers could take it to the Government's new scheme.

Peter Scott is the project's architect and said he would persist with the HCC development application.

"We're just dealing with the planning scheme that we're dealt with at the moment, and we're doing the best we can to see how we can comply and deal with that scheme," Mr Scott said.

'Tasmania needs planning consistency'

Brian Wightman from the Tasmanian branch of the Property Council of Australia welcomed the proposed new scheme.

He said Tasmania would be aligning its laws with other states including New South Wales, Victoria and South Australia.

"In Tasmania with planning we must have certainty and consistency," he said.

"We don't have that now because we have 29 councils and 30 schemes. Nowhere in the world has that sort of set up."

20 greens and community groups were also at the Town Hall forum, concerned the changes would remove transparency in the development planning process and overlook local environmental and heritage values.

Consultation on the legislation will begin early next year and the Government expects to implement it by the end of 2017.