Commercial building cost inflation rose to 29% in the second quarter of 2007 from 16% during the first quarter of the year, the FNB Commercial Property Finance Property Building Cost Index showed on Tuesday.

The index reflects the average building cost per square metre, as priced by building contractors when winning tenders. As such, it reflects the combination of contractors' input costs, their own pricing power which varies over time due to market conditions, and the standard of the property developments in question.

While the retail and office property building costs indices have been showing increases, the industrial property sector has seen some tapering off in its inflation rate, the index showed.

The retail property sub-index showed a year-on-year building cost inflation of 39.5% for the second quarter, followed by office space with 26.2% and industrial space inflation of 13.9%.

"One should not read too much into the tapering in building cost inflation in the industrial property sector. Its index showed strong growth in 2006, running a bit counter-cyclically to the other two sub-indices, and was probably due for a breather coming off a high base," said John Loos, FNB property strategist.

He noted that the renewed surge in the index broadly tracked the producer price index for building materials, which experienced a lull in 2006 before seeing its inflation rate climbing as 2007 approached.

"The rise suggests a significant input cost push effect, especially as it comes at a time when there exist a feeling that especially office rentals still need to adjust further upwards in order to make many more projects viable, and in so doing alleviate a vacancy rate," said Loos.