A skyscraper in two weeks: Does China’s building boom hide bigger problems?

China's fast-paced construction industry has long been the subject of discussion and for some countries, jealously with some construction companies building skyscrapers in as little as two weeks. But are the foundations of the China's break-neck building on shaky ground?

In April last year, a Chinese construction company Broad Sustainable Building claimed itself to be the world's fastest builder after erecting a 57-storey skyscraper in just 19 working days. The company, which specializes in prefabricated construction, prepared 90 percent of the structure at the factory before the site work began and then assembled the remaining 10 percent structure like a jigsaw puzzle at the site.

"I think this goes back to an innovative form of modular Lego like construction," Alastair Campbell, Investment Manager-Asia Pacific at Kames Capital told CNBC via email.

"This is not a case of a Chinese builder throwing up a building as fast as possible in order to make a quick buck and a sign of lax building regulations. Rather the intention was to demonstrate an efficient building technique, after all the Chinese have built a lot of huge apartment blocks over the last 20 years."

Photographer | Collection | Getty Images

However, such speed has raised questions on the buildings' sustainability, longevity and safety even though some analysts have said that the construction companies follow international building standards and regulations.

"Undoubtedly, there are poorly constructed and designed buildings in China, particularly due to historically poor application and oversight of planning and building laws. However, I suspect that the application of laws has probably been tightened and standards enforced since the anti-corruption drive initiated by President Xi Jinping in 2012. The penalties for breaching building laws can be severe," Kames' Campbell told CNBC.

Housing is one of China's biggest economic drivers but analysts have warned that slowing property prices and weakening returns may be pointing to a problem in the broader economy.

Construction data released this month revealed that property investment in January-July rose 5.3 percent from a year earlier, data from the National Bureau of Statistics (NBS) showed, slowing from an increase of 6.1 percent in January-June in 2015. Property sales by floor area grew 26.4 percent, down from 27.9 percent.

"The stock of unsold property in China has ballooned in recent years," Fathom Consulting said in a research note on China. "But this has not prevented new construction from taking place. Starts continue to outpace sales, adding to the stock of work in progress, while the time taken to complete a project has lengthened considerably."

A housing bubble?

So does this mean there is a strong demand for new homes in China? Desmond Soon, lead portfolio manager for the Legg Mason Western Asset Opportunities Fund told CNBC that the general trend of increasing urbanization in China would support demand for new homes in the longer term and in turn aid the growth of the Chinese economy.

"But, at the more micro city-level, we do note that the strength of demand can diverge significantly as Tier 1 and leading Tier 2 cities with more vibrant economic backdrops seeing far greater housing demand as opposed to Tier 3 and Tier 4 cities with weaker economic fundamentals and even negative population growth seeing continued inventory glut. "

The bigger challenge, however, some analysts believe is not the demand in the housing market but the quality of pre-existing housing stock that needs upgrading and re-development in many cases.

"The quality of the housing stock will require upgrading as the wealthier population demands better housing, and there is undoubtedly a proportion of the housing stock that is of poor quality which will require reconstruction," Kames' Campbell told CNBC. "However, population growth is slowing and aging. The government is introducing taxes that increase the holding cost of vacant apartments."

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