Oversized air-con ledges - some almost the length of a bus - in a newly built condominium in Sengkang have cast the spotlight on a loophole that allows developers to build them without having them counted as part of the gross floor area (GFA).

Yet, they are allowed to charge home buyers for that same space.

Each year, Singapore's private property owners pay $780 million for air-con ledges, estimates consultancy International Property Advisor chief executive Ku Swee Yong.

It is time that the authorities take away the GFA exemption for these ledges - just as they did for planter boxes and bay windows nine years ago, said industry experts and home buyers. The Urban Redevelopment Authority made the move in 2008 after noticing that some developers had been exploiting the loophole for profit (see background story).

STOP CHARGING BUYERS Fewer buyers would feel 'cheated' if they were not charged for the air-con ledge. MR KU SWEE YONG, Chief executive of International Property Advisor.

Other features that take up space

Once a fad, bay windows and planter boxes have disappeared from condominiums of late. "Nowadays, shoebox flats are packed wall to wall to maximise the internal space," said analyst Chris Koh of property firm Chris International. Bay windows and planter boxes used to be exempt from gross floor area calculations - an incentive by Urban Redevelopment Authority (URA) to encourage developers to include such features. But buyers had to pay developers for the space as it came with the unit. It was thought that bay windows would make for interesting elements, while planter boxes were introduced to provide greenery and visual relief to high-rise condos. But in July 2008, the URA reversed the exemption, saying it had led to "unintended and undesirable consequences" and "negated the objective of the (gross floor area) exemptions for these building features". For instance, the floor plan of one unit at Suites@guillemard showed that about 15 per cent of a 24 sq m apartment was taken up by these features. Whether such an exemption will be removed for air-con ledges remains to be seen. Mr Koh said: "One way to get around the abuse is to create an acceptable range of sizes for such ledges, depending on the unit's floor area." Rachel Au-Yong

The GFA refers to the maximum amount of liveable space that a developer can build on a plot of land.

Currently, air-con ledges up to 1m in width do not count towards the GFA of a condominium development. Yet, they are considered strata area that developers can charge buyers for as part of their units. This has led to abuse, charge some.

In particular, a band of some 200 home owners in La Fiesta in Sengkang are now irate over "massive" air-con ledges in their homes.

They calculate that 645 of the 810 units - about 80 per cent - have ledges that are 4m or longer. This exceeds 5 per cent of their floor area, which experts say is an acceptable upper limit. Some ledges even measure 9 sq m - over 7 per cent of the 127 sq m four-bedroom units. Most house two compressor units.

In contrast, four- and five-room HDB flats have ledges of about 3 sq m, which can fit two compressor units. This works out to about 2.7 to 3 per cent of the floor space.

Having paid, on average, $1,174 per sq ft of space, the La Fiesta residents estimate they have paid about $18 million in unused space for their air-con ledges.

Architectural technical manager Tien Geok Beng, 53, who leads the group, acknowledges he cannot be compensated financially.

He said: "What I hope... is for home buyers to be wary of paying unnecessarily for an oversized and useless air-con ledge. I also want the authorities to close the loophole. If there is no use for such a space, you should not allow developers to design a huge space at the expense of buyers."

A meeting with local developer EL Development last September ended with it saying it was not obliged to make any changes.

"The size and extent of the air-con ledge were given and acknowledged by purchasers before the option to purchase was issued," a spokesman told The Straits Times, adding that the ledges were designed to be big enough to fit all compressor units and to give electricians enough space to work on.

The URA told The Straits Times it does not have a guideline for ledges as it already considers "a myriad of factors in assessing whether air-con ledges are reasonably sized".

Since May 2012, developers have also been required to provide a drawn-to-scale floor plan of the unit and a detailed breakdown of the unit's various spaces.

Both the Real Estate Developers' Association of Singapore and the Singapore Institute of Architects said they do not set guidelines on air-con ledge designs.

But Mr Ku argues ledges should be re-classified as non-strata areas: "Fewer buyers would feel 'cheated' if they were not charged for it."

•Additional reporting by Yeo Sam Jo