These Japanese tiles were manufactured by tile company Danto Kaisha, and each features the image of a fingered citron – a symbol of happiness, longevity and good fortune. Each tile also has an illustration of a pomegranate, which represents fertility; and peaches, a symbol of long life.
Made by British company Alfred Meakin, these English tiles each feature a depiction of a pink water lily and were used to decorate the townhouse’s staircase.
While the manufacturer of these Art Nouveau-style tiles is not known, they are believed to have originated in Belgium or England.
The townhouse’s airwell, a common feature in shophouses, allows its insides to be naturally ventilated and lit, as air and sunlight from outside the house can be let into it.
This is the front facade of the shophouse, which appears narrow, with a width of about 7m.
It has a depth of 50m and a height of 14m. It occupies a land area of about 296 sq m and has a gross floor area of 447 sq m.
Three weather stations have been placed at 141 Neil Road – in the front yard, in the airwell on the ground floor, and in the backyard.
Five sets of data are measured at each station – airflow, temperature, humidity, solar radiation and air pollution concentration.
Temperature sensors have also been placed on the building’s V-shaped roof tiles, to give researchers a sense of how hot the tiles get at different times of the day, which may inform where solar panels are placed in the future to power the building.
These thermometers have recorded temperatures of up to 58 deg C before, which Dr Joshi says suggests that the tiles are absorbing sunlight and not reflecting enough heat. He adds that as the tiles get heated, they could transfer heat to the rest of the building, making it uncomfortable for its occupants.
Studies on the building have also shown that a natural wind tunnel runs from the building’s front to its rear – through the main door facing the front yard, the airwell, and a door that leads to the rear yard.
Dr Joshi says the establishment of the wind tunnel might explain why the property’s past residents chose to rest their furniture against the walls – as seen in old photos – possibly to leverage the wind tunnel to cool themselves.
He had initially thought the wind tunnel would flow instead from the building’s rear to its front as he thought a breeze from the sea would run from the back of the house.
A study of the temperatures in 141 Neil Road’s reception room also found that in the day, the indoor temperature is up to 4 deg C lower than the outdoor temperature, while indoor and outdoor temperatures are more closely aligned at night.
Overall, the digital twin helps researchers visualise real-time conditions within the property, such as this view that shows the temperatures recorded in various spaces within the townhouse at one point in time, without external cooling or fans.
Does ArClab hold lessons for Singapore’s other heritage properties?
At ArClab’s official opening in November 2022, National Development Minister Desmond Lee said he hoped the research facility would support building owners in the maintenance and repair of heritage buildings, and also study how sustainability and liveability can be imbued in built heritage.
As heritage maintenance and protection is an ongoing process, it is hoped that the methods and approaches that will be used at ArClab can be applied to other heritage buildings in the future.
Based on URA data, about 4,300 of Singapore’s conservation properties have been repaired according to the agency’s conservation guidelines as at end-2019.
Although many of these properties underwent major repairs at the point of conservation, such works are often not one-off, as weathering over time will necessitate future repairs to reinstate and refurbish key features of the buildings.
A URA spokesperson says that through its programmes, ArClab has demonstrated how tools such as digital twins can support the building management and conservation industry in Singapore.
Dr Joshi hopes methods used to repair 141 Neil Road can eventually be applied to other heritage properties here, many of which he says were built using similar materials – lime and clay bricks.
“Everything is applicable. I want to keep it as real as possible – I’m not going to use anything secretive,” he says of the forthcoming repairs and the materials that will be used.
But some aspects of the conservation works, such as leveraging the elements for natural ventilation and cooling, will require buy-in not only from building owners and tenants, but the public.
Conservation consultant Eugene Lin of Fivefootway Consultants says that from his experience, clients – including office, restaurant and retail shop tenants – expect a certain level of thermal comfort, which means air-conditioners will remain the norm when it comes to cooling shophouses.
Meanwhile, architectural conservator Ho Weng Hin says that with climate change, traditional buildings designed and built a century ago will need to be sensitively adapted to today’s conditions.
Mr Ho, the co-founder of architectural conservation consultancy Studio Lapis, cites the increase in extreme rainfall events in recent years, which older buildings are not always equipped to deal with, as they do not have a rainwater discharge system that can keep up with today’s volumes.
While supportive of traditional building materials and methods, he says that any application of such methods on a larger scale can happen only after rigorous and systematic scientific testing and careful analysis.
Dr Joshi believes ArClab is on the right track.
“We want to influence policies and conservation standards. This will be a tangible example rather than just theory. I can teach theory in the classroom – why do I have to come here?” he says.