The juvenile tuatara at Kiwi Birdlife Park are quickly outgrowing their enclosure, and plans for a new $50,000 extension have been drawn up.
Tuatara have highly specific requirements for light and humidity, and senior wildlife keeper Paul Kavanagh said the intention was to allow natural light to filter into the enclosure as well as artificial heating.
Included in the plans were "lots of water features", a sprinkler system, and "a lot of visual barriers" for the six juvenile tuatara.
As tuatara were very territorial, "this reduces aggression, [having] places where the less dominant can hide", he said.
The park is also home to four adult tuatara who are kept in a separate outdoor enclosure.
The project was the largest undertaken at the park in recent years and, while there were other minor projects, Mr Kavanagh said this was "a whole other ball game".
Construction would start as soon as funding allowed, and an architect was reviewing the plans at present in the hope the enclosure would open in 2013.
On Saturday, some of the profits of Queenstown business Zip Trek's "locals day" were donated towards the enclosure.
The tuatara were in their breeding season at present and the females needed specific areas in which to lay.
Some of the eggs laid had been sent away to be assessed and monitored, since the soil temperature determined what sex the tuatara would be.
As part of the park's captive breeding programme, many of the hatched tuatara would be released into suitable sites.
"The future is looking bright but there's a long road ahead.
"The eggs take an incredibly long time [to hatch] ... up to 15 months sometimes."