The Jakarta administration is taking a step toward creating more energy-efficient buildings by drafting green regulations for future and existing structures.

The regulations are being drafted by the Jakarta Property Management and Control Agency and will form the legal grounding for the green designs, agency head Hari Sasongko said Wednesday.

"Many cities in the world have applied the green building concept. We're late in doing so and it's time for us to follow suit as we face limited energy resources and fuel price increases," he told The Jakarta Post at City Hall during a seminar on green buildings.

"The agency is currently drafting regulations to enforce the concept," he said.

The seminar, which was attended by city officials, architects, building consultants, city planners and environmentalists, is the administration's first step toward the implementation of green buildings in the capital, Governor Fauzi Bowo said.

Many buildings in the city are classified as polluters because they are the city's largest energy consumers and largest waste producers, Hari said.

"It is hard to encourage developers to voluntarily erect green buildings because the designs are costly", he said. "That's why we need regulations to enforce greener buildings. We will stipulate incentives and punishments in the regulations."

He said governments in other countries offered lower land and building tax rates for those applying green designs. "We'll see whether such incentives are possible here."

In addition, he said, the regulations would be applicable to existing and future buildings.

"Existing buildings will have to make some adjustments," Hari said.

Green buildings capture sunlight through a transparent roof that illuminates the interior, while natural wind blows through architectural airways to provide ventilation.

A building is also classified as environmentally friendly if it produces low levels of waste and carbon.

"The concept is all about decreasing the use of air-conditioning and energy consumption through lights by using a ventilation system," Hari said.

"We will also promote greeneries for building roofs."

Fauzi said green designs would also be applied to public buildings.

Architect and urbanologist Ridwan Kamil said at an international seminar energy-saving designs were urgent for the densely populated capital as it had little space for green areas.

"The simplest way to make existing buildings greener, particularly for high-rise buildings, is to at least start by greening their roofs," he said.

A green roof, he said, would lead to an immediate drop of 1 to 2 degrees Celsius in a building's interior temperature.