New Zealand practice Studio Pacific Architecture have developed alternative designs for a planned film museum in Wellington backed by Lord of the Rings director Sir Peter Jackson.

The Movie Museum and Wellington Convention Center, which will cover more than 10,000sq m (107,639sq ft) of prime waterfront land in the city’s central business district, will house memorabilia from the sets of Jackson’s movies and the creations of the acclaimed Weta Workshop.

Studio Pacific have presented Wellington’s City Council with two visions for the project. The first design – which was developed initially and meets the NZ$135m (US$97.3m, €87m, £75.4m) budget approved by the council earlier this year – is functional, modern and fairly minimalistic.

In contrast, the second design features a much more detailed aluminium exterior inspired by the head of a giant fish caught by the mythological Polynesian hero Maui. Both designs are the same on the inside.

While the second option would cost an additional NZ$15m (US$10.8m, €9.6m, £8.3m) to build, it has won the support of members of Wellington’s council who feel it would better reflect the museum’s international significance.

"We wanted to look at options to improve the quality of the building and [first proposed] design,” said Wellington’s deputy mayor Justin Lester, according to Radio New Zealand. “Because it's such a special building, quite internationally significant we thought we could possibly do better, and should probably do better.

"We're going to have people travelling from all across the world to come and see and experience the location. We tasked the architects to come up with something special and I think they've done that.”

According to Lester, the extra cost falls within the city’s broad budget. The design decision will debated and decided in an upcoming council meeting.

The three-storey development will be owned by the council. The Movie Museum will be a tenant on the first two floors for an initial 25-year period, with a 1000-plus-seat Convention Centre on the top floor.

Jackson and Weta founder Sir Richard Taylor – who worked with the director on the Lord of the Rings trilogy and King Kong – have invested millions in the museum and will help design its interior exhibitions. These will highlight New Zealand’s acclaimed makeup, costume and special effects industries.

According to the council, the project is expected to boost the regeneration of Wellington, generate significant additional visitor expenditure, cement the city’s image as the film capital of New Zealand and improve liveability.

Construction could start as early as January 2017. Initially the museum was planned to open in 2018.