The Housing Board introduced the Joint Selection Scheme in 1996 in a bid to preserve community ties.
It allows different households to choose replacement flats together under the Selective En bloc Redevelopment Scheme (Sers), so that they can live near each other.
Initially, applicants had to be neighbours who lived on the same floor, and they had to choose the same flat type at the new site, said HDB deputy chief executive Yap Chin Beng.
"But the rules changed after requests from good neighbours who lived on different floors."
In January 2008, the scheme was enhanced to allow up to six Sers households to request the joint selection of replacement flats together.
20 YEARS OF SERS
22 AUG 1995: The first Sers site is announced, comprising 16 blocks at Boon Tiong Road and Tiong Bahru Road.
JUNE 1996: The Joint Selection Scheme (JSS) is introduced. It allows affected Sers households to choose replacement flats together. They can choose only new flats of the same type.
MARCH 1997: The JSS is reviewed. Up to four Sers households can select replacement flats together if they are on the same floor in the old site, but they can choose different flat types.
JULY 2004: Sers owners can apply for new flats outside the designated site, enjoying the same rehousing benefits as all Sers residents.
2007: The HDB starts to consult Sers residents on common facilities at the new site.
JANUARY 2008: Up to six households can select replacement flats together. They need not be on the same floor or block at the old site,.
JANUARY 2011: Sers residents get priority for new flats outside the replacement site, with 5 per cent of supply set aside under the Resettlement/Relocation/ Tenants' Priority Scheme.
JUNE 2014: For new flats outside the replacement site, 10 per cent of supply is set aside for Sers residents. Sers residents at the Central Provident Fund drawdown age or older have the option of a two- or three-room replacement flat on a 30-year lease. Instead of the previous 20-per-cent discount - up to $30,000 - on the subsidied prices of replacement flats, Sers residents get a fixed sum in the form of a Sers grant - $15,000 for singles, $30,000 for families or singles living together.
They also no longer needed to be on the same floor or even the same block. So far, about 3,700 households, or a tenth of all Sers households, have applied for a replacement flat under the Joint Selection Scheme, said HDB.
Sisters Ida and Idy Loo, and their mother, Madam Yew May Hua, used to live in three separate flats in Block 114, Bukit Merah View.
When the block was selected for Sers in 2010, the sisters asked for two adjacent replacement flats, while Madam Yew sold her old unit and moved in with her younger daughter Ida. "We are very close, so it was natural that we wanted to live together," said Madam Ida Loo, 43, a trading operations executive, who has a five-year-old son, Jayden.
As Madam Idy Loo is often overseas for work, her sister helps to take care of her three children. Madam Idy Loo's eldest child, Ms Fion Tan, 23, said she and two siblings enjoy living next door to their grandmother. "It's great because Ah Ma always cooks us our favourite dishes, like dark sauce chicken."
The Joint Selection Scheme has proven more popular in some estates. The Sims Drive site, selected for Sers in 2005, for example, has the highest number of households who applied under the scheme - 228 out of 1,517. More than a fifth of the households at the Zion Road site selected for Sers in 2006 also opted for the scheme.
Neighbours Lai Su-Cheng and Leong Yoke Lin met more than 10 years ago when they were staying in the same block in Teban Gardens Road. After the block was selected for Sers, they moved to the same new block on the same road in 2012. Said Madam Lai, 67, a housewife: "We're quite close. We would always stop and chat when we bumped into each other."
It is this personal touch that Madam Leong, 53, cherishes. Said the part-time cleaner: "It's always comforting to have familiar faces around."
•Additional reporting by Janice Heng