The 193-year-old Ying Fo Fui Kun building in Telok Ayer Street, which has been shuttered for restoration works for the past two years, will reopen as a free public gallery next year.
This is part of the clan association's drive to promote Hakka cultural values, said its president, Professor Lai Ah Keow.
He told The Straits Times that the proposed Hakka History Documentation Hall in the building will have various sections such as ancestral roots; trades; Hakka culture, fashion and the arts; and influential personalities.
Prof Lai started amassing Hakka artefacts two years ago. He has made 20 trips to Meizhou in China's Guangdong, the ancestral home of most Hakkas here, to retrieve Singapore-linked artefacts and to study Hakka history.
He is also collecting them from the community here and contributing some of his own items such as an ang ku kueh press. Ang ku kueh are red glutinous rice flour cakes filled with mung bean or peanuts.
Among the artefacts that will go on display are letters from Hakka migrants in Singapore to their families in China. Called "qiao pis", these scraps of paper detailed the sum of money remitted home in the 1800s and 1900s.
"These everyday items are rare. Many have either been discarded or damaged over time. If we don't start collecting or documenting them, we will lose a key period in our history," he said.
The two-storey building, which was declared a national monument in 1988, is now undergoing repairs after it was affected by construction work nearby, said Prof Lai.
The building had been used by the clan largely for committee meetings, and music and dance practices. The clan has 2,000 members today. It also owns a compound, in Commonwealth Lane 9, that is home to an ancestral hall and 2,700 tombstones.
Ying Fo Fui Kun was built near the old shoreline, just three years after Raffles landed in 1819.
It functioned, among other things, as a rest stop for Hakkas after the long journey from China. Over time, the association also set up a free medical clinic and started classes for Hakkas.
The Hakkas ventured into various trades in Singapore. They included the cultivation of pepper and gambier, pawn-broking, shoe-making, basket-making and Chinese medicine shops.
There are about 230,000 Hakkas in Singapore, and they form the fourth-largest Chinese dialect group here. The largest group is the Hokkiens, followed by Teochews and Cantonese.
Some influential Hakkas here include the late founding prime minister Lee Kuan Yew and Aw Boon Haw, also known as the Tiger Balm King.
On the clan's role, Prof Lai said: "Today our social responsibility has changed. We have a new mission to educate people on Hakka culture."
He hopes that camera-touting tourists will also venture into the gallery as part of their exploration of the stretch which has a high concentration of national monuments such as the Telok Ayer Chinese Methodist Church, Al-Abrar Mosque and Thian Hock Keng Temple .
One of the association's committee members, businessman Charlie Lee, 43, said he has been helping to organise cultural activities to draw in youth for the past decade or so.
He believes the permanent gallery will be a timely addition.
Mr Lee said: "A lot of people identify themselves as Singaporeans. Few realise where their ancestors are from. The gallery will hopefully generate awareness in people about Hakka culture and tradition."
• Those who would like to contribute Hakka artefacts to the Hakka History Documentation Hall can e-mail Professor Lai Ah Keow at firstname.lastname@example.org