The trust has recently asked Horowhenua District Council to let it move into a council property.
Mr Girling said the trust's landlord wanted to sell the Harbour St section with the property market buoyant.
Tony Murdoch had let the property cheaply to the trust under the expectation it would then raise the funds to buy the property from him.
In 2014, Mr Girling said he expected to purchase the property in 2016.
Mr Girling this week said the trust could stay at Harbour St until the end of this year. If it had not raised funds by then for its centre, it would rethink its plans, he said.
The trust has asked HDC if it could lease the Holben Pavilion at Foxton Beach.
It told HDC it would like to build several other buildings on the site and develop wetlands there.
Mr Girling this week said the trust's environmental education programmes were running well and Holben Pavilion would be a good place for them.
HDC has said the pavilion was a poorly utilised community space and Holben Reserve under-developed, though the area behind the pavilion was used for local events.
HDC last week resolved the Foxton Community Board consider developing a Reserve Management Plan for Holben Reserve and Foxton Beach and take into account the trust's request during that process.
The trust made headlines last year after being formally warned by the Ministry for Primary Industries for leaving animals to die in live capture traps. An MPI spokesperson said at the time the trust failed to meet its Animal Welfare Act obligations.
Mr Girling said the trust immediately halted trapping when it learned of the problem and had no plans to restart.