Man in Charge of Rejuvenating Site of Clark Air Base Seeks Investors

green city A rendering of the planned Clark Green City. Bases Conversion & Development A Bases Conversion & Development A

CLARK FREEPORT ZONE, Philippines—On land that once belonged to the largest American military base outside the U.S., Arnel Casanova envisages not just a new city, but a new type of city for the Philippines.

Mr. Casanova, president of the Bases Conversion and Development Authority, the agency charged with regenerating the vast estates left behind by the U.S. military when it left the nation in the early 1990s, is trying to create a blueprint for modern, sustainable development in a country whose urban centers are polluted, congested and sprawling out of control.

Clark Green City—his proposed Philippine city of the future—is that blueprint. The Philippine government and Congress both have given Mr. Casanova the go-ahead to begin work on the Green City on land that once belonged to the U.S. Air Force's Clark Air Base, and which the Bases Conversion and Development Authority now runs.

But that is only the first of many hurdles.

Ecologically sustainable cities have been built elsewhere, but nothing like the carefully master-planned Green City has been attempted in the Philippines. That is the problem, say skeptics in the real-estate industry, who fear investors might not buy into Mr. Casanova's vision.

Imagined as a counterpoint to the sprawling capital, Manila, Green City will comprise seven parts open space to three parts development.

The city is intended to be walkable and bikeable, with effective mass transit. It aims to attract top manufacturers and technology firms to provide high-quality jobs, and will offer affordable housing to avoid social divisions like Manila's combination of gated enclaves for the rich and slums for the poor.

"Our vision is a metropolis that will be a benchmark for urban development in the Philippines," says Mr. Casanova, a Harvard graduate who, at 44 years old, is the youngest president of the Bases Conversion and Development Authority.

Development in the area, 60 miles northwest of Manila, has been taking place for years. The former base was reinvented as the Clark Freeport Zone in the 1990s, and has been moderately successful in attracting companies, including Convergys Corp.CVG -1.87% , Texas Instruments Inc. TXN -1.37% and Yokohama Tire Corp., thanks to tax breaks, a capable local workforce and the possibility of 100% ownership of local operations for foreign firms, a perk available only in the Philippines' special economic zones.

But the Green City, which would sit alongside the Clark Freeport and be more than twice its size, would potentially elevate Clark to a higher economic level. Mr. Casanova says the site, at 9,450 hectares or 36 square miles, will take 25 years to develop, or more, and eventually be home to 4 million Filipinos. Supporters hope the completed project will be able to provide nearly 1 million jobs, and produce $36 billion in annual output, roughly 4% of national gross domestic product.

These targets will be met only if the city grows according to plan, and that is far from guaranteed, real-estate professionals have warned. Yet the plan's supporters insist the Green City has to happen, if only to provide the country with an alternative to the unchecked urban sprawl that could otherwise prevail. Demographic projections point to a crisis unless the Philippines changes the way it plans and builds its cities. Fifty million Filipinos—half the country's population—live in cities today, but that could rise to 90 million, or 70%, by 2030, according to official forecasts.

"Between now and 2030, we'll need 100 new cities," says Felino Palafox, Jr. , the founder of Manila-based architecture firm Palafox Associates. "[The Green City] is very aspirational—they're trying to replicate the quality of life in Singapore—and it's a good concept," he says. "But how do you carry it forward?"

Mr. Palafox recalls watching the Green City dream fizzle before. He was part of a team that first designed Clark Green City in the 1990s, but the plan fell victim to shifting political priorities. Now, Mr. Casanova has revised and updated it.

Even real-estate professionals who doubt the Green City's viability still hope that it can succeed. "Any project that is looking to decongest Manila is welcome, the country needs it," says Gerard de Guzman, senior manager at Jones Lang Lasalle, a property consultancy. "But getting people and companies to move there will be a can of worms."

Infrastructure programs are typically slow in the Philippines, Mr. de Guzman points out, but companies will want to know that the highways, power supply, water and other utilities they need are in place, or on the way, before they commit.

Clark does have advantages, Mr. de Guzman notes. Its previous life as a U.S. military estate means it has ample quantities of buildable space. The airbase itself has been rebooted as Clark International Airport. Subic Bay, another former U.S. base, and now a civilian port, is nearby.