In the 1980s and 1990s, housewife Leong Lye Chan, 57, would squint hard while walking along the dark and gloomy corridors of the HDB block where she rents a flat.
She would perspire as she waited in the muggy corridors for her son after school.
In 2004, both ventilation and lighting at Madam Leong's Block 217 in Ang Mo Kio Avenue 1 improved significantly following changes made by the HDB.
Another rental block that was improved under the pilot programme was Block 1 in Holland Close.
Following the pilot, HDB will do the same at other older rental blocks built in the 1960s and 1970s in areas such as Bukit Merah, Kallang and Bedok.
These places house most of the older rental blocks, and the refurbishment will start in 2020.
Despite the tenants' positive feedback about the 2004 pilot, the works were not extended to other blocks in view of the rental demand and supply situation at the time, said an HDB spokesman.
A rental block typically has one-or two-room flats along both sides of the central corridor. Save for sunlight and wind sneaking into the corridor through open spaces at the lift and staircase landings, the rest of the corridor is mostly unlit.
To improve ventilation, HDB will create more openings along the corridors by removing some flats on each floor of the rental blocks, Senior Parliamentary Secretary for National Development Sun Xueling said yesterday.
The tenants living in the affected units will be moved to similar units in the same building or nearby rental blocks. "HDB will work closely with local organisations and the relevant agencies to ensure a smooth transition," she added.
Nationwide, HDB manages about 230 rental blocks, but lighting and ventilation improvements will be for blocks built in the 1960s and 1970s that have long corridors with flats on both sides, she said.
"We are looking to start preparation for the improvement works later this year," she added.
For Madam Leong's block, two columns of one-room flats were removed near both ends of the wide 10-storey block. Before the pilot, only the centre of the building had openings for air and light to enter.
Now, each floor is lined with 24 units, with two 5m-wide open spaces near the ends to facilitate cross-ventilation.
"Last time, the corridor was too dark. When people walked past us, we couldn't see them. Now, it is better because older people can see and hold the handrails while walking. It is also more airy," said Madam Leong, who has been living in her one-room flat for 32 years with her 31-year-old son.
Families also use the open spaces to dry their laundry, store their wheelchairs and bicycles, and chat with neighbours.
She added: "Every afternoon, I sit with my neighbours around a foldable table to chat about life and drink tea. Then, we return to our houses at 4pm to cook dinner for our families."