Private tutor Kay Tan had just gone to bed close to midnight one day in July, but sounds of drilling and beeping vehicles woke her up.
Since then, the 25-year-old, who is eight months pregnant, has hardly had a good night's sleep, as upgrading works at the nearby White Sands shopping centre in Pasir Ris Central often go on at night and into the wee hours of the morning.
"I can't fall asleep and I'm kept up till 3 or 4am," said the resident of housing project Pasir Ris One, just across the road from the mall.
Other residents have found the nocturnal noise disturbing too.
"It's quite bad," said human resources consultant Charles Goh, 30. "You can hear drilling, knocking and metal bars being transported. I'm surprised that they are allowed to work at night."
You can hear drilling, knocking and metal bars being transported. I'm surprised that they are allowed to work at night.
MR CHARLES GOH, a Pasir Ris resident
Some, like secretary Nazeera Noordin, 35, have resorted to shutting their windows and balcony doors at night.
Said Ms Nazeera: "A lot of my neighbours are frustrated. One of them even shouted at the workers from his balcony."
Irate residents have lodged complaints with both the mall and the National Environment Agency (NEA), which regulates noise levels from construction sites.
The NEA said it has received 43 complaints from 19 different people about the din since March.
Under its rules, construction work is permitted at night, but noise levels at worksites less than 150m from residential buildings cannot exceed 55 decibels between 10pm and 7am. Such a volume is comparable to normal conversation levels, according to the NEA. The distance between White Sands and the nearest Pasir Ris One blocks is about 100m.
NEA has issued two composition fines to Gennal Industries, the firm doing the works - one for carrying out works on a Sunday in February, and another for exceeding the noise limit in July.
The agency said it will issue another composition fine to the contractor for busting noise limits on the night of Sept 7.
Companies that exceed noise limits can be fined up to $40,000.
The NEA has also notified the firm to confine its working hours to between 7am and 10pm. This curb will kick in on Thursday.
But, Mr Alvin Ng, 33, project manager of the worksite, said his team plans to appeal against the fines and work-hour restriction. He told The Straits Times that the noise monitoring meter for the worksite also picks up sounds from the road.
"It records the noise of buses and cars passing through. Sometimes we get notifications from the meter even before we start work."
The NEA said that if needed, officers will visit worksites to check on noise levels with hand-held noise meters.
Ms Stephanie Ho, deputy chief executive of AsiaMalls Management, which runs White Sands, said noise barriers have been installed to "contain the noise" from works done within the building.
Pasir Ris One residents, who moved in earlier this year, however, pointed out that works are also done outside, and at late hours.
The mall's upgrading, which started in April last year, is expected to be completed early next year.
Ms Ho said certain work can be done only at night for safety's sake.
Mr Ng noted that, for instance, works near the Pasir Ris MRT station can be carried out only when trains are not running. "We are also working on the mall's facade and need to use boom lifts and scissor lifts - big machinery which will occupy the roads. So we have no choice but to use them at night. As for their beeping, it's a safety requirement - I can't switch it off."
Mr Ng said some residents had gone over to yell at his workers. "It's not like we want to work at night and disturb them," he said.
He added that, where possible, his firm tries to ease the noise, such as telling workers not to throw metal pipes on the ground.
But some residents look on the bright side.
Said Ms Nazeera: "Ultimately, we will benefit from the new facilities and shops. We are all looking forward to them."