Macquarie Point stadium roof in doubt as cricket authorities petition Tasmanian government for redesign

Macquarie Point stadium architects will need to either re-design the stadium's roof or eliminate it completely to appease cricket authorities who say the sport cannot be played at the proposed Hobart arena in its current form.

In a letter to the Tasmanian government, obtained by the ABC, Cricket Tasmania and Cricket Australia raised "significant concerns" about the effects of shadows cast by the roof's supporting structure over the centre wicket, and their ability to stage fixtures at the venue.

"We are of the view the current roof design will mean the stadium is unlikely to be conducive to hosting test matches and could also be challenged in hosting One Day (50 over) and T20 (20 over) fixtures," the letter reads. "This is not an outcome that either CA (Cricket Australia) or CT (Cricket Tasmania) wants, and CT will be strongly challenged by its members to advocate for an alternate solution. "For this reason, we would like to discuss with you what opportunity there is to consider a stadium design option that does not have a roof, or that has an operable roof."

The proposed stadium still needs to be approved by Tasmania's parliament. (Supplied: Macquarie Point Development Corporation)

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The bombshell letter, co-signed by Cricket Australia chief executive Nick Hockley and Cricket Tasmania chief executive Dominic Baker, was received by government officials almost two weeks ago.

It lists stadium orientation, "premium product provision", drop-in pitches and turf growth as cricket's priority design-related issues.

It also reiterates that "both CA and CT remain committed to and supportive of the stadium project, and wish to see it progress".

But it's the fixed roof, and its potential effect on player and spectator conditions, that has proved a hurdle.

The proposed Macquarie Point stadium roof may need to be redesigned. (Supplied: Macquarie Point Development Corporation)

In July last year, Cricket Tasmania endorsed stadium designs unveiled by Cox Architecture — but new shadow modelling presented to it earlier this year revealed problems.

"This includes the impact of the shadows cast from the roof structure on the field of play, particularly on the cricket pitch block throughout the day, and ultimately the implications for what forms of cricket the stadium could and could not support," the letter reads.

The stadium's lead design team, Cox Architecture — and German firm Schlaich Bergermann Partner, who designed the stadium roof — have been working on mitigation options, including temporary measures.

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A spokesperson for the Macquarie Point Development Corporation, who is behind the stadium project, said the design process was "ongoing, and includes user engagement and workshops".

"A range of options are being explored including structural, materials used in the roof covering and adaptive measures to provide consistency in light and shadows cast," they said.

However, Cricket Australia and Cricket Tasmania have not been convinced by the solutions so far offered up by the design team.

"While we appreciate the recent efforts of the project team to explore mitigation options for shadows, we are of the view that they are either unworkable, in that they do not eliminate the shadows or they are temporary in nature, introducing significant potential problems relating to playing conditions, venue operations and broadcast quality," the letter reads.

Cricket crucial for stadium business case

A roof, along with a 23,000-seat capacity, and the stadium's Macquarie Point location have long been non-negotiables for the AFL and its club presidents, who voted to grant Tasmania the 19th license on the condition the stadium was built.

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Cricket content is crucial for the economic viability of the estimated $775m stadium, which is only so far guaranteed to host seven AFL fixtures per season, among 44 other assumed events such as future Matildas and NRL fixtures.

Cricket Tasmania has also begun the process of transitioning out of Bellerive Oval, on the proviso that major cricket fixtures would be played at the Macquarie Point stadium from 2029.

The AFL is steadfast in its position.

"There has been no change to the conditions contracted for a 19th AFL team license in Tasmania, which includes the commitment of a 23,000-seat roofed stadium at Macquarie Point," the league's general manager of corporate affairs, government and communications Brian Walsh told the ABC.

If the build were to go ahead as currently planned, it would be the world's largest timber-roofed stadium. (Supplied: Tasmanian government)

But the Macquarie Point Development Corporation could reinterpret what constitutes a "roofed stadium", if a redesign is absolutely required.

"All stadia have roofs. The extent of the roof, however, varies. Roofs are required to provide weather protection to patrons from rain, and operational functions such as to support speakers, services and supporting lighting structures," a spokesperson said.

Under the original design, the transparent fixed roof would be supported by timber and steel beams, with ethylene tetrafluoroethylene (ETFE) pillows spanning 160 metres.

As well as hosting sporting matches, the stadium has been proposed as a live music venue. (Supplied: Macquarie Point Development Corporation)

Complicating the process further is the project of the state significance planning process, which the stadium is currently subject to and is halfway complete.

It is unclear what a significant design tweak would mean for the process, which is due to finish in September.

If the Macquarie Point stadium is built, it would be the world's largest timber-roofed stadium, and it was hoped the stadium could host the world's first indoor test match.

The Tasmanian government has been contacted for comment.

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