Tag Archives: BCA

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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Two GLS sites to adopt PPVC

Two upcoming Government Land Sales (GLS) sites at Yishun Avenue 4 and Jurong West Street 41 will need to adopt Prefabricated Prefinished Volumetric Construction (PPVC), an advanced technology in construction.

These sites are scheduled to be released for sale in November and December 2014 respectively.

This is in line with the revised Building Control (Buildability and Productivity) Regulations announced by the Building and Construction Authority (BCA), which now requires using labour-efficient construction methods and building design to improve construction productivity.

From 1 November 2014, projects are required to use prefabricated and standardised components. Specifically, all non-landed residential developments are required to adopt drywall as internal partitions for dry areas. New projects will also have to be built based on standardised floor heights and building components (such as precast staircases, precast refuse chutes and doors).

Next, they have to meet higher minimum Buildable Design and Constructability standards to make buildings easier to construct and encourage the use of efficient construction methods and processes.

Lastly, residential non-landed sites, including Executive Condominiums (EC), and the residential component of mixed-use sites sold under the Government Land Sales (GLS) programme will have to adopt productive technologies for projects, such as using Prefabricated Bathroom Units (PBUs, pictured).

The adoption of PPVC will also be imposed on selected GLS site.

PPVC involves assembling whole rooms or apartment units complete which are produced off-site and installed on site in a Lego-like manner. PPVC also enhances worksite safety as prefabrication of the building modules are done in factories.

Other projects which have adopted PPVC include a student hostel at Nanyang Technological University (NTU) and a building extension to the Crowne Plaza Changi Airport Hotel.

An upcoming Executive Condominium (EC) in Sembawang by City Developments Limited (CDL) will also be built using PPVC, making CDL the first developer in Asia to adopt PPVC for a large-scale residential project.