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Picture it. A grassy patch sloping gently down to the water or a vacant lot on a sought-after street. For creative homebuyers, it is the perfect blank canvas, a chance to work with architects on a unique design that's perfect for their family.

But such sites are becoming "rare as hen's teeth", according to sellers, and that's reflected in the price.

A Trade Me search last week revealed plenty of empty residential sections costing $1 million-plus, with some upwards of $2.5m.

Ten of the most expensive found by the Herald on Sunday ranged in size from 315sq m to 1251sq m.

Mainly in the upper North Island, the beachfront and clifftop lots were a mixture of subdivided sections and land on which earlier homes had been demolished.

All were in sought-after areas, such as Auckland's North Shore and the suburb of Remuera, and holiday hotspots such as Papamoa, Whangamata and Mt Maunganui.

An empty lakefront section on the shores of Lake Pupuke in Takapuna was the most expensive, with a $2.7m asking price.

The 1188sq m, north-facing site is big enough for one large home and the only vacant section in the area.

Auckland Architecture Association spokesman Roger Dowling said growing populations were making empty lots rarer in New Zealand cities, particularly Auckland.

He said it was more common for people to subdivide big sections than demolish existing homes. "What you find is that those empty pieces of land are either part of an estate, or very difficult sites, which leads to more costs for building."

Other costs could include strict resource consent requirements for removal of trees.

"Someone with a spare $2m can't just buy [a section] and put a house up. That's getting further out of reach of the common person," Dowling said.

The costs don't put everyone off, but Murray Dyson, of Tippetts Real Estate, who is selling the Lake Pupuke section, said there was a "fairly narrow" market for a site of high value.

Dyson said it was difficult to know whether the asking price would be reached because there were few comparable sales in the area.

"[The buyer] can build a place that is tailored for their options, and that's quite special and quite rare."

Dyson said the site was appealing because it was large and the home on it had been demolished.

He said there had been solid interest and at least two offers in the past four to six months.

Frank Vosper, of Tauranga's Vosper Realty, said empty sites were also attractive because they eliminated the need to alter existing homes.

Two sections found by the Herald on Sunday had buildings - a $2.2m section on Waiheke Island with a tiny bach in one corner, and a Christchurch section with a home on it.

Vosper, who is selling a beachfront Papamoa section valued at more than $1.5m, was unable to comment on the possible sale price, but said local land values had risen substantially.

About 40 years ago, Vosper said a small bach and section would have sold for about $30,000, but seaside sites were "as rare as hen's teeth".

"It's the first section like this in my nine years of real estate sales."

The second most expensive section we found had a capital value of $2.4m and was also on the North Shore, with clifftop views towards Rangitoto.

Agent Graeme Tonkin, of MRE Property in Milford, said the original home was demolished late last year, leaving a large section behind.

Such opportunities within the city were "absolutely rare", Tonkin said, especially in high-value areas such as Milford. "[Buyers] have to knock down a pretty decent house sometimes to get a piece of land now."

People who bought such sections would be willing to pay up to $4m for a house, but they preferred to buy the land and design their own home, Tonkin said.