Water restrictions have been lifted for Christchurch and Banks Peninsula but some Waimakariri residents must still boil their water and their river is contaminated.

When the tremors return, residents at one Christchurch rest home band together with cups of tea and company.

At least 22 commercial properties and 50 homes in the small quake-damaged North Canterbury town of Kaiapoi have been deemed unsafe, with its mayor admitting the town is changed forever.

Most schools in the quake-devastated Canterbury region are not likely to open until Monday, the Education Minister says.

The final bill for the Christchurch earthquake may reach $4 billion, almost double initial estimates, Treasury Secretary John Whitehead said afternoon.

Aftershocks are continuing to hit Canterbury with one measuring 4.1 the latest in a series today that also included a 5.1.

The state of emergency in Christchurch has been extended a further seven days following an aftershock of 5.1 on the Richter scale this morning.

An open source online map has been set up to help Cantabrians find help nearest to them.

Stricken homeowners and workers will start receiving compensation and emergency payouts within days as Christchurch's earthquake bill threatens to exceed $2bn.

Rebuilding up to 100,000 damaged and destroyed homes in quake-hit Canterbury could take years, a building executive says.

The Christchurch earthquake is expected to provide a much-needed lifeline for NZ's beleaguered construction sector.

Allan Hubbard believed his self-righteous hype - sadly, so did we.

Christchurch was "inevitably going to be brought to its knees" by an earthquake because of the nature of the ground it stands on, a scientist says.

"It was like a giant had picked up our house and was just shaking it, shaking and shaking," said one resident.

Peter Dunne's bill is unfair, unaffordable and unlikely to happen, writes Brian Fallow.

The Govt has announced details of a new 'Savings Working Group' designed to come up with ideas to improve NZ's savings record.