They may be Singapore's only two surviving dragon kilns from the 1940s and 1950s, part of a once-booming brick industry here, but their fate is up in the air.
The wood-fired dragon kilns - their distinctive shapes resemble a dragon's tail and smoking head - at 85 and 97L, Lorong Tawas, in Jurong are part of a fascinating history.
Up till World War II, Singapore was home to at least 20 smouldering kilns. Some of the Jurong kilns used to produce latex cups used by nearby rubber plantations.
However, they sit on government land earmarked for long-term development.
And the National Heritage Board (NHB), the statutory body some would think is responsible for their safe keeping, actually has no power to conserve the site.
This is even though its impact assessment and mitigation division deemed the kilns historically unique and of artistic value last August, and managed to persuade the site's owner, the Singapore Land Authority, to extend its lease by three three-year terms.
The board's division, the Preservation of Sites and Monuments (PSM), has the power only to gazette - or preserve - national monuments based on stringent criteria.
For the site to be conserved, the Urban Redevelopment Authority (URA) would have to step in. Even then, it would have to weigh the needs of the agencies involved in the site - this includes the JTC Corporation, which runs the CleanTech Park there - and the future land needs of the area. The agencies involved must come to an agreement.
So, after surviving for decades, the dragon kilns' future is clouded due to a hodgepodge of rules on heritage and conservation matters, and overlapping or conflicting development priorities.
Other historic sites and monuments are falling through the cracks too.
In 2008, five heritage bridges along the Singapore River were put on the conservation list by the URA. Under the law, conserved structures and buildings must retain their original structure and achitectural elements.
They must also be sensitively restored or repaired carefully, should the need arise.
But some of these structures, which fall under the charge of their site owners, the Singapore Tourism Board and the Land Transport Authority, fell into disrepair.
This would not have happened if a government body had been appointed to galvanise and see to it that different agencies and developers work towards the same goals.
Architectural conservators, historians and civic groups say the problem lies in the overlapping and unclear roles of the three bodies charged with heritage matters - the NHB, PSM and the URA.
The situation today
The NHB promotes heritage appreciation through managing its national museums, and documentation and outreach efforts.
Under its umbrella is the PSM, which provides legal protection for national monuments - these must have socio-historical, cultural and architectural value on the level of national significance - and offers monument owners guidance and regulatory support.
Then there is the URA, established in 1974, and which is charged with studying old buildings for possible conservation as part of land use planning.
For a structure to be worthy of conservation, it needs to fulfil the URA's requirements, including having architectural, social and cultural significance; the rarity of the structure; and the contribution to the environment.
Experts have given these bodies the thumbs up for their good work so far.
They applauded the NHB's landmark move to set up an impact assessment and mitigation division last July to study and act as consultant on the effects development has on the country's heritage. The new division came about as part of an internal reorganisation.
Comprising a group of conservation architects, historians and researchers, its job is to conduct impact assessments of redevelopment works on heritage sites and structures and work with parties involved to establish mitigation measures.
It acted as mediator, working with the Housing Board and Singapore Heritage Society, to incorporate heritage elements into the new Bidadari housing estate, for example. It also worked with civic group My Community, the URA and Housing Board to help conserve several landmarks in Queenstown, Singapore's first satellite town.
NHB chief executive Rosa Daniel said NHB plays the role of heritage promoter, facilitator and regulator. "Each role is important and we seek to find the balance that best serves the needs of a more discerning public and a more complex operating environment."
Experts acknowledged the URA's work as well. The authority has close to 7,200 buildings in its conservation stable.
They noted that its latest gazette in June saved warehouses, public housing flats and social institutions such as health-care facilities and a library - marking a shift from the large numbers of shophouses and black-and-white colonial bungalows it started out saving.