China's economy may have decelerated to its slowest pace in 25 years, but the country’s appetite for tall buildings still appears to defy gravity.

For the eighth straight year, China in 2015 built the world’s greatest number of towers that are more than 200 meters high.The 62 new skyscrapers it built represent 58% of the global total constructed in 2015 according to a new report by the Council on Tall Buildings and Urban Habitat.

“China continues to build more of these towers than any other country, and with over 300 such buildings under construction at the time of this report, it’s plausible to assume that the country’s momentum will continue in the near future,” said the Chicago-based institute.

“The country’s long-term prospects are more uncertain,” the report said, adding that the China’s pivot to a consumption-led economy could mean that “large-scale government-funded construction projects might begin to take a backseat.”

Construction activity in housing has clearly declined in the last two years, and the building of offices is only just starting to slow down. On Tuesday, China said its gross domestic product grew 6.9% last year, the slowest rate in 25 years amid policymakers’ attempts to overhaul the economy and foster more domestic demand.

Completions of office buildings in China grew 8.8% last year, down from 12.7% in 2014, while construction starts fell 10.6% last year, reversing the 6.7% growth recorded in 2014. Lackluster demand in all but the biggest cities has left rows of empty towers swathed in sheets of construction dust and sparked concern among analysts and developers.

City planners often cite China’s focus on urbanization to justify the construction of such skyscrapers and other massive property projects. But commercial property owners outside China’s upper-tier cities often struggle to find tenants.

“In many cities outside Beijing and Shanghai, urban planners have overly optimistic estimates of demand and compel developers to build projects that have labels – such as the tallest, or the biggest -- to embellish the profile of the city,” said Carlby Xie, research director of China at Colliers International, a property consultancy. “Some are only now coming around to calculating the profitability of such buildings.”

Last year, 29 Chinese cities completed towers that are more than 200 meters tall, with Nanjing, Nanning and Shenzhen ranked at the top with five each, the Council on Tall Buildings and Urban Habitat said. The 632-meter Shanghai Tower was the tallest building to be completed in 2015, and it is currently the second tallest skyscraper in the world, behind Dubai’s Burj Khalifa at 828 meters.

Of 20 of the tallest buildings completed in the world last year, 12 were in China. Apart from the Shanghai Tower, Forum 66 Tower 1 in Shenyang is in fourth place and Chongqing World Financial Center is sixth. They are followed by Nanjing International Youth Cultural Center Tower 1 and Fortune Center in Guangzhou lower down the list.

Industry insiders said the number from China could have been greater if not for the holdup on official approvals for building completions. Local authorities usually cite insufficient fire safety features in withhold approvals, but developers and consultants say in private the bottleneck is due in part to China’s ongoing anticorruption campaign.

--Esther Fung. Follow her on Twitter @estherfung.