Fundraising committee member Helen Ingrams said about $3000 was raised at the sale from furniture, clothing, books and artwork donated by members of the centre and the public.
It adds to a total of now $48,000 the centre has raised to date to address water seepage in its basement, which had produced black mould on walls and "turned green" part of the floor.
"We grow moss on a regular basis down there now and it’s climbing up the walls."
Renovating the basement would take between two and three years to complete and could cost "several hundreds of thousands of dollars", Ms Ingrams said.
"Everything helps.
"We were just so delighted that people came from so far and wide to the garage sale, and the atmosphere was really good.
"Having events like that just proves how good community is and what Dunedin people can achieve."
The centre’s annual garage sale was its first fundraising event for this year, the proceeds from which could cover "the lion’s share" of a further seismic assessment.
Its next fundraiser would be its annual raffle around the middle of the year, Ms Ingrams said.
