House-hunters are so terrified of being locked out of the soaring property market that they're making their real estate agents sign agreements which get them out of selling their house if they lose out on a new home.

Others are negotiating much longer settlements on their sales to allow them more time to search.

The latest Real Estate Institute figures show homes in the Auckland region sold in an average of 30 days - compared with 41 days in 2008 - and it was as low as 26 days in Onehunga.

Ray White Pt Chevalier real estate agent Noeleen Woods said two vendors in Waterview had had their lawyers draw up clauses in their sales and purchase agreements this month that stated that if they were unsuccessful in bidding at auctions of other homes, their own house sale would not go through.

The arrangement is a first for her decade-long career.

"They're just a little bit nervous. They don't want to be without a home, of course.

But this is a different market than I've ever worked in before. It's a tough market for those youngsters. Or for anybody wanting to move from their smaller first home into their second home.

"They can spend lots of time going to auctions and never be successful and then be left without the house that they've got."

The clause is explained to open-home attendees, Ms Woods said.

"Everybody gets that explained to them as soon as they look at the house so it's very fair. They don't have to go on looking through it or putting an offer in if they know that clause is there and they don't want to do it."

One couple put their home on the market for five days and had the clause as they hoped to bid on another home. But they did not get a suitable offer so took the house off the market and didn't go to the auction.

One house hunter who went to an open home last weekend told the Weekend Herald she was surprised when the clause was explained to her.

"I'm currently looking for my tenth family home, and I've owned houses overseas, but this was the first time I've heard about such demands from a vendor.

"I was wondering, 'Why should I bother getting emotionally and financially involved in the house only to have the vendor lose the auction?' I even asked if the vendor would really pull the house off market if unsuccessful, because there is so much expense involved in listing a property.

"I didn't want to spend money on a builder's report, lawyer's fees and have the stress of negotiating if the vendor didn't have any hope at winning the auction."

Custom Residential co-owner Keith Dowdle said he was seeing an increasing number of house vendors negotiating three-month settlement periods.

"That's quite a long time; your classic period would be six to eight weeks. People are certainly concerned about being left outside the market ... so if they're selling before they've bought, they are selling on long settlements so then they've got time to go out and buy. And that's probably because they don't want to be renting. The main concern for people is that they don't want to be outside the market with the way the market is climbing."

Mr Dowdle said more people were selling during the winter when stocks were typically lower, and prices were higher. A three-month settlement would take them through to spring, with the hope that they would have more choice.

The battle for high-end rentals has also become extremely competitive as people selling their homes at rapid speed for record prices need a house immediately while they look for a new property to buy.

They are desperate for short-term leases, said Jenni Olausen of Unlimited Potential. There was a lack of rentals available in the $1500-plus price range offering leases between three and six months.

"Two years ago, it was people who were maybe doing a renovation; they would look to rent those high-end properties for maybe a year or even two years. We're not seeing so much of that," Ms Olausen said.

"What we are seeing is people doing a quick sell ... and then wanting shorter term. And what has happened with some of those people is they've had to end up taking it a little bit longer than they would have wanted to do, perhaps taken on a nine-month lease to secure a house."

Couple hang on to home until they get dream house

Tracy Hill and her partner fell in love with a home on the next street over from their Waterview property. So they put their own house on the market with the intention of bidding on the new one at auction.

But they knew the market was tough and it might not be that easy. So they called their lawyer.

When any potential buyer walks through their Alverston Rd property, they're told a sale won't go through if the couple are unable to secure a new home.

"We just thought the safest way to play was to put that clause in because we didn't want to be left without a home," Ms Hill said.

"It was about getting the right house. Once upon a time you could go out there and there might be 50 or 100 to choose from. But we spent three hours on the internet looking at houses in the sorts of central areas that we could afford and would like to live in, and we found two. People aren't selling ... because they're worried about what mortgage rates are going to do and all the rest of it and you think 'What if we can't find the right one'.

"We don't want to end up with two houses that we can't afford to pay for," Ms Hill said.

The couple, who have two young sons, were due to bid on the other house in Fir St tomorrow but have not yet received a suitable offer on their home.

They have owned their four-bedroom dwelling for seven years but want something bigger and more modern.

"This isn't a super-modern house, it's 15 years old but still a contemporary home and the one the next street over is very new, it's five years old," Ms Hill said.

"We wanted something contemporary and we really like Waterview and there's very little here. We didn't want to live in a bungalow or weatherboard or brick house."