They join 14 other properties that sold at auction in the Illawarra over the week, generating a clearance rate of 64 per cent according to CoreLogic, based on 25 reported results.

That figure is down from the 67.4 per cent figure recorded the weak prior and well down on the 93.9 per cent recorded in September.

The properties, at 11 St Johns Avenue and 13 St Johns Avenue were listed for separate sale but were both held by the same vendor.

Despite selling agent Jay Peterson of Raine & Horne Wollongong having shown "120" groups through in total, and having issued "multiple contracts", with 15 minutes to go on auction day nobody had turned up.

"They were going to be my first two absolute no shows in two years," Mr Peterson said.

At the last-minute a "hero" developer, who hadn't previously inspected the properties and plans to construct a duplex on the combined site, showed up and registered to bid for both.

Number 11 sold for $851,000 and number 13 for $951,000 - with the developer placing a $1000 bid against a vendor's bid in both cases.

The vendors had owned the former for more than two decades, and had acquired the latter in 2012.

Both properties, each consisting of three bedrooms, are currently tenanted and were described by Mr Peterson as "liveable but needing a lot of work".

Despite the successful sale, Mr Peterson said the lack of bidders was a stark contrast to auctions he'd held over the past two years, where it was common to have five or more registered bidders.

"To come to auction day and to be standing there in the rain and to have no one there to bid was quite bizarre ... [these were] decent properties that first home owners can come and purchase for under $1 million," he said.

He said that buyer energy had been showing signs of "changing" and prospective buyers were likely "fed up" with trying to keep pace with the fast-moving market in the Illawarra.

In addition, an increase in stock was giving buyers who were still actively looking more choice, he said.

Number 11 is situated on an 822 square metre block, while number 13 is slightly larger at 878 square metres.

Further south, a 19.3 hectare block at 120 Woollamia Road, Falls Creek, south of Nowra, sold for $4.52 million shortly after the virtual hammer fell on Saturday.

The block, which has the potential to be subdivided into two-hectare blocks, subject to council approval, was sold to three investors from Wollongong.

A three-bedroom home with open plan living and dining areas is already in place at the property.

Selling agent Cindy McGillivray of McGrath said that there were a total of 17 registered bidders, with a "strong" opening bid of $3.5 million.

Vendor Barbara Hansen and family, selling due to downsizing plans, had held the property, known as 'Little Haven', for two decades and had selected her birthday as the auction date.

She described the anticipation leading up to the auction as "somewhat traumatic" but said she was very happy with the result, and celebrated with "champagne and nibblies".

She and her husband had farmed on the property, which they'd driven past several times in 1999 before finally being convinced by a selling agent to take a look at the property.

"We walked up the paddock it was so wet we were in gumboots. [At that point] we knew the property would be good to us," she said.

Mrs Hansen hoped that the new owners would retain the existing house as part of any development.

"I'd like to think somebody would be living in the house here, it's a lovely house and we've had a lot of happy times in the house," she said.

It was incredibly rare to find a block that of this scale and proximity to hot coastal markets like Huskisson, Ms McGillivray said.

"It's rare to have something this big, this close and this cleared - that's the main thing, it doesn't have trees on it so it's just ripe for development," she said.

A downsizing couple from the Southern Highlands were behind a pre-auction offer that saw a four-bedroom home in Oak Flats sell at the top of its price guide.

The property, at 19 Lyne Street, had been scheduled for auction on December 3 before the couple made a $1.3 million offer prior to the second open for inspection.

Selling agent Dragan Balaban of Belle Property Illawarra said Oak Flats didn't have a reputation as a desirable place for downsizers but that this was fast changing.

He credited the home's renovation as the key to the successful sale.

"It's a beautiful renovation that was done in 2013 and you can see they kept the character and the charm throughout," he said.

The property had been listed with a guide of $1.2 million to $1.3 million.