Gregory White, commercial director of CIT Property Consultant Co, said infrastructure development created a huge boost to the property market as mass-transit services would make developments more accessible. The extensions of the Ratchapisek, Thon Buri and Sukhumvit lines would be very popular in the near future.

About 130,000 square metres of office space is scheduled to open up within the first half of next year, Mr White said. One prominent Grade A office building on the Asoke-Ratchadapisek Intersection will offer 45,000 sq m in the second quarter of 2008. Colliers said about 7.45 million sq m of office space was now available with occupancy of 6.45 million sq m and an overall vacancy rate of 13%.

Total supply of grade A office in CBD stood at 1.3 million sq m, and 0.8 million sq m in non- CBD areas. The supply of grade B space in the CBD is at 2.4 million sq m. Monthly rent for grade A office space in the CBD is 650-750 baht/sq m, while it's 500-545 baht/sq m outside the CBD. Rent for grade B office space in the CBD is 525-550 baht/sq m.

Mr White said about 300,000 sq m of new supply would be added to the market next year, while demand may reach 200,000 sq m this year, depending on the political situation. The company forecast the vacancy rate next year at 14-16%, which already accounts for government agencies moving to the new government centre in Chaeng Watthana.

However, vacancy rates in the grade-A sector should increase as most new developments offer grade-A office space. Continued rent increases would depend on investor confidence. ''At the moment, there are many uncertainties and we don't know if the outcome of political issues would move the market up or down. We see positive signs and believe that there would be business expansion and more foreign investment next year,'' said Mr White, who previously was a national director of Jones Lang LaSalle.