The Christchurch earthquake will cost up to 15 billion NZ dollars (11 billion U.S. dollars) and knock gross domestic product growth back by 1.5 percentage points, but New Zealand's Treasury predicts a silver lining in 2012 as rebuilding gets underway.

"We estimate that GDP growth will be around 1.5 percent points lower in the 2011 calendar year solely as a result of the February earthquake," Treasury said on Sunday in its monthly economic indicators for February.

"From 2012, the recovery will bring a sizable boost to residential, commercial and infrastructure investment, placing upward pressure on prices depending on the rate of rebuilding."

Treasury said the earthquake had a large cost in human and economic terms and emphasized its estimates were early and tentative.

"The outlook for the New Zealand economy was weaker even before the earthquake as domestic demand was soft despite income gains from high commodity prices.

"The earthquake will have a negative impact on economic activity in 2011, but a positive impact from 2012 as the rebuilding gets underway."

Treasury said domestic developments occurred against an international backdrop of political unrest, high commodity prices and rising inflation.

"Even before the February earthquake, it was apparent that the economy was weaker in the second half of 2010 and early 2011 than we had expected in last year's Half Year Update. Growth in the second half of 2010 was weaker than previously expected and the recovery from the September earthquake was slower than we assumed, reflecting the extent of the damage, ongoing aftershocks and the complexity of the repairs and rebuilding," it said.