Kiama Municipal Council gave the green light to Miltonbrook's 31-lot subdivision, known as Chapel Hill, in December.

The four-hectare site off Drualla Road is located behind Jamberoo Public School and adjoins the historic St Matthew's Catholic Church and cemetery.

The majority of lots are between 800 and 1000 square metres, with a handful of larger lot sizes up to 2455 square metres.

Miltonbrook business partners, siblings and sixth generation Jamberoo residents Lawson Fredericks and Jennifer Macquarie have a strong connection to the area and were students at the neighbouring Jamberoo Public School.

"What's surprising is that this land remained undeveloped for so long," Mr Fredericks said.

"It was zoned for residential development in June 1969, before I was born.

"Housing developed around this site, but the previous land owner was a farmer who continued to use this land for grazing cattle and had no interest in developing.

"Fortunately, when he did want to sell, he contacted our father, Neville ... the old farmers' network is still there and useful."

Ms Macquarie said she'd had 200 inquiries for the 31 lots.

"There is a shortage of residential land across the Illawarra and vacant lots in Jamberoo are as rare as hens' teeth," she said.

The 31 lots will be offered for sale on August 17 via a "published reserve" auction held at Jamberoo School of Arts.

Ms Macquarie said with this method, the price list was circulated in advance so that prospective land buyers knew what price the vendor would accept for each block.

If there was only one person interested in a particular block, it would sell at the reserve price.

If there was more than one person interested in the same block, the block would be sold to the highest bidder. Pricing starts at $315,000. People will be offered an opportunity to walk over the blocks a week before the auction.