To enter, guests must pick their way through a shallow pond that brims with aquatic plants, balancing on rocks that wobble just a fraction.
Then, there is the rope-and-basket pulley system that owner Clarence Chua devised to haul up food deliveries, and lower bundles of Thai and sweet basil from his rooftop garden in return.
Passers-by and patrons of the Spanish restaurant next door gape. Sometimes, when the harvest is bountiful, Mr Chua sends down extra for them.
Watching all this from atop feels like being in on a secret, a serendipitous find, the sort of place one chances upon at the recommendation of a Airbnb host or hotel concierge.
Guests can book the event space for private gatherings such as movie screenings and wedding proposals, or take part in an experience that comprises hands-on urban farming, getting up close to a beehive, honey tasting and enjoying farm-to-bar drinks.
Even the farm’s existence is serendipity at play. Mr Chua, who is also general manager of landscaping company Country Cousins, found the shophouse in July while looking for a place to house five foreign workers.
He had previously moved his employees out of various foreign worker dormitories from March, after the first Covid-19 cases were detected there.
After shuttling them around various apartments over the next few months, including a condominium he owns in Bugis, Mr Chua wanted to settle them in more permanent quarters.
But landlords were leery of renting to foreign workers.
“The tenant profile doesn’t fit,” he was told repeatedly.
His cousin, a real estate agent, finally found the Siglap shophouse, which Mr Chua describes as “love at first sight”.
The second-floor home, where five workers now stay, was well-kept. And to his landscaper’s eye, the empty concrete roof brimmed with possibility.
“Urban farming has become popular, but I have done only ornamentals so far. I already know how to make plants thrive – it was just a matter of putting in new plants. This was the perfect chance to experiment,” says Mr Chua, who is married to a public servant.
The couple, both 37, have two sons, aged 3½ years and 10 months.
Mr Chua had previously built ponds, but not streams, for landscaping clients and took the chance to incorporate the latter, filling half of it with plants such as water hyacinth and water lettuce, and chlorinating the other half that leads to a children’s play pool.
Other experiments proved more hazardous.
While moving a metal shed from a storage facility to the rooftop, Mr Chua discovered a beehive in a corner.
Inspiration struck and the entomophile, whose former pets include scorpions, tarantulas and snakes, decided to introduce bees into his farm.
He put out a call to landscaping clients, offering free beehive removal if they discovered one on their premises, and learnt to relocate hives from books and YouTube videos.
In the beginning, lacking protective gear, he was once stung eight times on his face and had to get a steroid injection to bring the swelling under control.
Bees sting in clusters, he explains, as they release a pheromone to warn other bees of danger. The scent, a saccharine mix of nail polish and bananas, has now become a warning for him too.
Cloaked safely in bee suits, visitors face no such risk.
From behind a netted hood, we watch as Mr Chua explains bee behaviour, such as huddling together when they sense rain so as to protect the comb, or fanning their wings at the entrance of a hive to regulate the temperature within.
A honey-tasting session opens our eyes to the tastes, textures and colours of honey from around the world, from the warm, caramel notes of blue gum from Australia, to the woody and resinous dark amber pine honey from the Mediterranean.
We also hear from farmscaper Jeremy Beckman, who, together with Mr Chua, planted rows of Asian herbs such as laksa leaves, Thai basil and kaffir lime, as well as more finicky varieties such as thyme, sage and rosemary.
Mr Beckman, 35, explains what goes into a good potting mix as we layer soil with a bag of compost he has prepared.
“Good soil should not smell bad,” he says, and indeed the black mix, comprising waste such as leaf litter and horse manure, is odourless when I scoop it up with bare hands.
Cuttings of Thai watercress, pushed into the soil, take root easily and flourish by the kitchen window over the next few weeks with minimal effort.
We cap the experience with a sampling of cocktails, included as part of the package.
A bourbon smash, garnished with calamansi and mint and sweetened with stevia in its original plant form, is tangy and refreshing. And the evening ends on a sultry note with burnt sage garnishing Laphroaig whiskey, known for its smoky flavour.
Other seasonal drinks, such as a Bloody Mary when the tomatoes fruit or a gin and tonic with home-grown cucumber, are in the pipeline. Regardless of which plants bear fruit, they will make it work.
Mr Chua says: “Despite the pandemic, or perhaps because of it, The Sundowner was born. Even in adversity, there is always opportunity.”
The Sundowner Rooftop Farm Experience
Where: 705A East Coast Road
Duration: Two hours
Fee: $95 for those aged 13 and older, $65 for three-to 12-year-olds
Text: Clara Lock/The Straits Times