The sale is expected to net the iconic volunteer organisation more than $12 million, bringing to an end a debate that has deeply divided its 10,000-strong membership.

Delegates at this week’s annual conference in Griffith voted 397 to 142 in favour of selling the Greenknowe Avenue address, which has housed the association’s head office and residential club since 1955.

The association plans to use the proceeds to buy a more modern, lower cost office building without an accommodation component, and with floors that could be rented out for additional revenue.

Its executive committee had argued it would be "an extremely questionable commercial decision" to hold on to the property, that it estimated would cost between $1.7 million and $3 million to upgrade.

State president Tanya Cameron said the vote was much closer than she expected, but the outcome meant the CWA could now begin looking into the sale process ‘‘and where we go to from here’’.

"I think this decision will mark the beginning of an exciting new time in the history of the CWA of NSW as we continue to adapt to meet the changing needs of rural women and families," Mrs Cameron said.

But the decision will also mark the end of the association’s modest 50-room residential club at Potts Point, which opened almost six decades ago to give country women a cheaper and ‘‘more homely’’ alternative to a hotel.

The decision means members who can currently stay at Potts Point for as little as $50 a night will in future stay with "an appropriate established accommodation provider" instead.

It is this change that has particularly dismayed the sale’s opponents, who argue that the residential club is an irreplaceable resource for rural and regional women while in Sydney, often during times of great need.

Anita Dulhunty, who had stayed at Potts Point while her late husband battled cancer, predicted the move would prompt people to leave the association.

"I think there will be a rapid decline in numbers now," Mrs Dulhunty said. "A lot of people are most upset by that decision."

Mrs Cameron said the association risked losing members whichever way the vote went.

"Obviously there will be some members who have been really quite upset about this possible sale, and so we have to recognise that they will be disenfranchised," she said.

"We’ll have to hope that we can all move forward and keep doing what CWA does best."