While most people buy their home with a loan from the bank - and then pay interest on the loan, meaning the house costs them much more than the initial purchase price - the Dews will only have to pay back the sum they borrowed to complete the purchase.
The scheme was launched in New Zealand in 2007 and modelled on the JAK Members Bank in Sweden which started in 1965. In New Zealand it is organised by the Living Economies group.
The Dews got involved five years ago when they started attending Saving Pools communal meetings hosted by the Living Economies. The following year they joined a group under the Wairarapa-based Saving Pool.
Mrs Dew said there were 12 members in the group when they first joined and now there are 18.
"We didn't know anyone in our group from a bar of soap, and it does take a lot of trust," she said. "Before joining, we got to know everyone by attending lots of meetings and pot luck dinners."
She said a member could only join if everyone in the group was happy.
"It's really important that the combination of personalities works."
Living Economies outline the risks of losing money but advise the pools on appropriate security measures.
Payments from the pool's accounts need two signatories, or will have other security measures in place.
Peter Luiten,associate of Living Economies, said there were almost 40 pools in New Zealand.
Mr and Ms Dew said they hadn't had any problems with their group and kept up regular communication with everyone.
"A lot of the people in our group, we would never have had met before, but coming together we now have a diverse range of skills," Mrs Dew said.
"Once a member wanted to take out a loan from the pool to move houses, but the group was able to resolve the problem without money - someone had a trailer and others offered labouring services."
The couple have also encouraged some of their 10 children to join.
"One of my sons took out a $3500 loan from the pool in 2015 to help pay for university accommodation and has already paid it back. My other son took out $15,000 in 2014 to pay for his wedding and will complete his payments in 2019."
Mrs Dew's son is paying $500 a month back to the pool. Of that, $250 will be interest-free loan repayments and $250 will be additional savings.
The Dews say that once they have repaid what they borrowed for their house, they will stay in the scheme and make use of it again.
"It's a weight off our shoulders that we wouldn't be paying thousands of dollars in interest to the bank," Mrs Dew said.
