New data has revealed the financial impact of the lockdown on the nation's housing market and identified the best and worst-performing regions.

Data crunched by OneRoof and its partner Valocity shows New Zealand property values have fallen just 1 per cent since the start of the Covid-19 crisis, as measured by a new index, despite a plunge in values during the four-week nationwide shutdown.

The situation is better than many pundits had expected, though it comes on the back of strong price growth in the months before the lockdown began.

Experts attribute the relative buoyancy to the low number of listings coupled with strong demand from buyers and record low interest rates.

Of the 15 major regions, 12 have seen declines since March 25 - the day before the country went into lockdown - with values in the remaining regions stalling.

Property values in the Greater Auckland region dropped 2 per cent on the index in the weeks after March 25, but have since recovered, and are now just 1.6 per cent off where they were before lockdown.

Similarly, New Zealand property values on the index dropped 2.4 per cent during the lockdown period but the surge in market activity since alert level 2 has seen them recover much of that loss.

Dollar-wise, Auckland City's median value on March 25 was $1.03 million. It now sits at $1.02 million.

Economists are still trying to quantify the likely impact of the pandemic on the country's housing market.

Global ratings agency S&P last week tipped New Zealand house prices to fall 10 per cent

However, OneRoof editor Owen Vaughan says the new index shows clearly that overall the housing market is doing better than was forecast at the start of the crisis.

"While the full impact of Covid-19 won't be clear until mortgage deferrals and the wage subsidy scheme come to an end, it seems the housing market has rebounded from the lockdown.

"The index shows that values in many locations are back to where they were at the start of the year, when the market was starting to run hot. The question for buyers and sellers is whether or not the bounce-back will be short-lived."

OneRoof and Valocity created the new index to solve the challenges of measuring a housing market that suffered an unprecedented shutdown and faces an uncertain future.

The index sets as a baseline property values on March 25, 2020. Every sale since that date has then been analysed and tracked, allowing subtle changes in the market to be measured.

Valocity valuation director James Wilson said: "When we looked at the market using traditional methodology, comparing activity now to activity 12 months ago, we saw that only two territorial authorities - Kaipara and Selwyn - have seen declines in property values and that 38 have enjoyed more than 10 per cent growth.

"This gives a false impression of what's going on in the market. Yes, property values are up but that's more a reflection of the fact that these locations were experiencing value growth in the three to six months before lockdown."

Wilson says the drop in sales volumes forced OneRoof and Valocity to look at a range of different market metrics, not just median sale prices.

"By breaking down what's been selling together with the nature of the housing stock in any given location allows us to track more effectively the actual changes in individual submarkets."

The index shows the impact of the lockdown and the extent of the bounce-back in each territorial authority.

The biggest fallers were North Shore (- 3.8%) and Christchurch (-3%). Others include Queenstown Lakes (-7.7%), Far North (-4.4%), Waitaki (-3.9%) and the Coromandel (-3.8%) - but those areas had low sales volumes so the numbers weren't as reliable.

The best-performer was Lower Hutt (up 1.1%). Rotorua was also high at 4.6 per cent as was Waikato (4%), Matamata (3.7%), and Kaipara (3.1%) but those areas also had low sales volumes.

Wilson says the index clearly shows the erosion in property values isn't a crash. "For example, North Shore values are where they were at the start of February, when the market there was picking up speed. Auckland City is back to where it was at the end of January," he says.

Loan Market mortgage adviser Bruce Patten said the market was busy, driven by a low number of listings and strong demand from first home buyers looking to cash in on record low interest rates.

"A lot of parents are helping children into properties because the cost of a mortgage is actually less than what they're paying in rent."

While this boded well, the real impact of the pandemic would not be known till thousands of homeowners came off their mortgage holidays in October to December.

This could see many people forced to sell their homes if they had lost their job and not found re-employment, he said.

Barfoot and Thompson national auction manager Campbell Dunoon said the company sold a 1950s three-bedroom home last week in double grammar zone for $3.584 million, more than $500,000 over CV, and at the end of last month sold what could be this year's most expensive piece of real estate - a 1960s clifftop home in Remuera that went for $8m.

And while many auction rooms are full, not everything is selling under the hammer. Some auction clearance rates have been low with properties selling for under CV.

Ray White chief auctioneer John Bowring puts recent successes down to not enough houses on the market to meet buyer demand.

"Even if the new normal is that we've only got half the stock [to sell], we've still got more buyers looking for properties. It's always going to be a supply and demand issue."

Harcourts Cooper & Co auctioneer Andrew North, who operates on Auckland's North Shore says supply is tight.

"Until we see a flood to the market, there'll be no fall in prices."

He suspects would-be sellers are choosing to renovate rather than trading houses.