The withdrawal applies to the residential areas including Dhanmondi, Gulshan, Banani and Lalmatia but Nikunja (South) has remained restricted.

But experts and city dwellers fear these areas will become concrete jungles with the withdrawal of the restriction and the rules will be violated by unscrupulous builders.

"The removal of height-ceiling will apply only to residential buildings and not to commercial ones," said Public Works Secretary Iqbal Uddin Chowdhury.

Only those will be allowed to raise buildings vertically who will keep certain space of the plot open in proportion with the Floor Area Ratio (FAR) and will design the building as per new building rules of 2006.

The order cancelling height ceiling will be applicable only in the light of Dhaka Building Construction Rules of 2006 and the six-storey height-limit will remain in effect in case of building designs prepared under the Building Rules of 1996, which is set to remain effective till January 31, 2007.

Height-limit withdrawal and the rules of 2006 will not be applicable to Nikunja (South) residential area. The height-restriction slapped by the civil aviation authorities will remain effective in Nikunja, as the area is located within the flying zone.

As per the FAR, the height of a building will depend on the open space spared of the plot on which the construction will take place, said the secretary.

"As per this rule, buildings will be allowed to grow vertically keeping adequate open space around every building to facilitate better environment, open air and easy movement," Chowdhury said.

The bigger the plot is, the more space a builder has to keep open but will get benefit of more floors taking the building further higher proportionately.

Architect Iqbal Habib of Bangladesh Paribesh Andolon (Bapa) said the height of a building would be determined by amount of open space left, permitted ground coverage with construction, size of floor and permitted buildable area under new rules.

Owner of a two-katha plot with a 20-foot wide road will have to keep 35 percent of the land but will be able to construct a building of 485.68 square metre space applying FAR standard, compared to 445.14 square metres under the old rules.

Similarly, a three-katha plot with a 20-foot wide road will have to keep a minimum of 40 percent open space but will have 752.72 square metres of buildable area compared to previous 682.81 square metres.

Owner of a five-katha plot with a 25-foot wide road have to spare a minimum of 40 percent open space of the land and will have a buildable space of 1304.58 square metres compared to previous 1080.83 square metres leaving 30 percent open space.

The buildable area will proportionately come down with narrower roads. A building owner may go to any height by increasing or decreasing the size of each floor area but has to remain limited within the permitted buildable area determined by FAR standard.

In case owner of an existing building intends to raise a six-storey building up to ten-storey, the owner has to demolish the old building, keep required open space and comply with the rules of FAR.

President of Real Estate and Housing Association of Bangladesh (Rehab) Abdul Awal said the bigger a plot is, the more benefit a building owner will enjoy as per FAR.

But experts have expressed apprehension of manipulation and violation of the FAR provision.

"Unscrupulous people will first build a high-rise as per the FAR leaving open space, but later on, they will occupy the open space some way or other," said Honorary President of Centre for Urban Studies Prof Nazrul Islam.

The city development controlling authorities have to be committed and honest to prevent the wrong use of the new building provision, he said. "But Rajuk is neither honest nor diligent to ensure effective application of rules."

"The already corrupt officials of Rajuk will indulge in corruption just because of their corrupt habit," Prof Islam said.

A Gulshan resident Shirin Shila said, "Unscrupulous people will turn the residential areas like Gulshan, Dhanmondi and Banani into aristocratic slums abusing the rule."

Shila filed a writ petition against the government order to convert six-storey residential buildings along Gulshan Avenue into eight-storey commercial buildings paying nominal fees. The High Court stayed the government order upon her petition.

Architect Iqbal Habib said, "The public works ministry should immediately forward a set of directions, as per the building rules requirements, on land use to the land ministry to prevent manipulation and violation of the building rules."

He put emphasis on the factors like Detail Area Plan (DAP) and addressing slum problems to make the new building rules effective and meaningful.

The Rehab president at a press conference on Saturday said it is just a wrong perception that owners of small plots will be losers provided FAR is applied.

The press conference was attended by Prof Nazrul Islam, Toufiq M Seraj of Bangladesh Institute of Planners, architect Khadem Ali of the Institute of Architects Bangladesh and Prof Abdullah Abu Sayeed of Biswa Sahitya Kendra.