Category Archives: Construction

Lightning protection or hazard? Metal features on roof..

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Some owners of penthouse units at condominium Bedok Residences have avoided using the barbecue pits and jacuzzis on their private roof terraces when they saw that the lightning rods connect to the metal rails and facades of the units (above). However, while it seems counter-intuitive, checks reveal that the roof terrace and accompanying balustrades are safe

Talks are under way to revise a building code that regulates lightning protection to address safety in the growing number of roof terraces in housing developments.

Residents in at least one condominium development have avoided using their own private roof terraces since July last year over such concerns.

The lightning protection system at mixed-use development Bedok Residences has the lightning rods connected to the metal rails and facades of the rooftop units.

“I don’t even want my domestic helper to clean the area since lightning can strike at any time,” said resident Dennis Lim, who is in his 50s.

As a result, he and other residents have avoided using their barbecue pits and jacuzzis on their terraces.

Another resident, Ms Tay Min Li, in her 20s, said: “If I touch the metal rail and the lightning strikes elsewhere, won’t I be electrocuted?”

While it may seem counter-intuitive, checks have revealed that the roof terraces and accompanying balustrades are in fact safe.

Experts explained that the lighting protection system reduces the risk of injury thanks to the concept of “equipotential bonding”, in which metal parts on the roof are earthed if they are connected to the ground.

When lightning strikes, its electrical current will follow the path of least resistance to the ground through the metal instead of the human body, said Mr Ken Jung, vice-president of the Singapore Electrical Contractors and Licensed Electrical Workers Association.

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Both the Building and Construction Authority (BCA) and developer CapitaLand Singapore confirmed that Bedok Residences’ lightning protection system was certified by a professional electrical engineer for its temporary occupation permit.

Professor Liew Ah Choy, who chairs the technical committee of the current lightning protection code, however, noted that given the increasing trend towards having accessible or private roof areas, the lighting protection code for roof terraces is being reviewed.

In its current state, the lightning protection code – Singapore Standards 555 (SS 555), which was introduced in 2010 – does not refer specifically to roof terraces, noted the National University of Singapore adjunct professor.

Similar systems can be seen at developments with publicly accessible roofs, such as Marina Bay Sands and the Pinnacle @ Dawson.

The Straits Times understands that one of the ideas mooted in the new lightning protection code involves parapet capping, where the entire edge of the roof is encased in metal.

Another possibility is a trellis, which functions as an enlarged lightning rod.

However, these fully metallic structures may actually look more alarming to some residents, said Mr Jung.

“Most people have a limited understanding as to how lightning works, so it is important to educate people on how a building’s lightning protection works,” he said.

The BCA spokesman said that as a precaution, residents who own units with roof terraces should stay indoors during inclement weather.

Most people have a limited understanding as to how lightning works, so it is important to educate people on how a building’s lightning protection works.

MR KEN JUNG, vice-president of the Singapore Electrical Contractors and Licensed Electrical Workers Association

 

Source : ST Singapore

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S’pore among 10 most expensive cities for construction

Singapore is the third most expensive Asian city to build in after Hong Kong and Macau, according to the latest International Construction Costs Index published by Arcadis, a global design and consultancy firm for natural and built assets.

Globally, Singapore is ranked 10th. New York is the world’s most expensive city for construction, followed by London and Hong Kong.

The annual Arcadis index analyzes the relative cost of construction across 44 major cities, and found that strong currency performance and significant resource constraints have seen these places command premiums of up to 60 percent compared with many European locations.

However, this price inflation comes at a cost, with the viability of major commercial and public sector schemes put at risk in these cities as prices continue to soar. Furthermore, rising costs and the falling value of currencies could restrict demand from emerging market investors in these areas, potentially triggering a shift in interest to lower-cost cities in the long term, noted Arcadis.

The consultancy stated that every construction market this year saw overall cost inflation restricted due to the drop in commodity prices. Particularly with oil, growing uncertainty over prices will have a long-term impact on the global construction industry.

Alan Hearn, Head of Buildings Solutions, Asia, said: “Singapore’s construction market has enjoyed a strong recovery since 2010. It is for this reason that the recent slowdown in residential and commercial markets represents something of a correction. In the private sector, both the residential and industrial sectors were relatively weak in 2015 and the office market also suffered due to oversupply.

“Looking ahead, continued investment in road and rail can be anticipated as these aspects of infrastructure have not received as much investment in recent years in Singapore.

“For Asia, China’s economic slowdown and weakening demand in many cities, including Singapore and Jakarta, mean that growth in the region is expected to ease as we enter 2016.”

Ho Chi Minh City, Kuala Lumpur, Bangkok, Bangalore and Taipei are among the world’s cheapest cities for construction, added the report.

The full report can be downloaded here.