"Right now we need donations and support so we can continue operating our conservation programme and to build the new centre," Stewart said,
"Our new site is currently a construction site and, until we can get everything signed off, we cannot have visitors at the new facility. The birds are also in temporary aviaries until we are able to build display aviaries."
She said there had been several costly hold-ups that had hindered progress at the new site with bad weather at the top of the list.
"We remain humbled to be able to be on Ngati Whakaue land and we are embracing the cultural aspect of what we do with the birds and acknowledging we are doing it on ancestral land."
The shift to Ngati Whakaue land came about as Wingspan's former lease came to an end.
"One of the main reasons for the move was so the organisation could expand and grow.
"We used to get 20,000 people through a year but by our business planning it looks like we'll be up to 100,000 people each year."
While the money for stage one is being sourced, the centre will continue its conservation, captive management and rehabilitation programmes.
"Until we come up with the $500,000 the doors will remain closed but we are targeting an August 18, 2018, official opening," Stewart said.
The Givealittle page, Save Wingspan, had reached a total of $4345.30 on Tuesday.