The first homes were expected to be built within the trust's Pāpāmoa housing development, Manawa.
"Quality housing is a critical post-Treaty settlement strategy for Ngā Pōtiki," Kingi said.
"The benefits to our members' lives through this scheme will positively impact many other areas of our members' lives such as health, general wellbeing, education, and whanau health."
Kingi said the scheme meant Ngā Pōtiki would contribute equity as a co-owner and Westpac would provide lending to hapū members on the "usual terms".
"The homeowners will be able to buy out Ngā Pōtiki once equity builds in their homes," she said.
Ngā Pōtiki chairman Colin Reeder was pleased the agreement had finally been signed.
"The Ngā Pōtiki Housing Shared Equity Scheme represents our desire to assist our people into home ownership," he said.
Westpac NZ chief executive David McLean said the initiative helped Ngā Pōtiki members overcome the barrier of needing a large deposit and lowered their loan servicing costs.
"As the owner's income or equity rises they can then take on a greater stake until they own the whole property," he said.
"With housing increasingly unaffordable in many areas, we think shared equity is a
solution that has strong potential."
Waiariki MP Tamati Coffey said Ngā Pōtiki was setting a template for Māori landowners and trusts to be able to follow.
"With anything that helps Māori whānau to be able to get into houses is always going to be welcomed," he said.
Tauranga City Council economic development and investment committee chairman Max Mason said it was encouraging to see Ngā Pōtiki leading "a nationally significant housing initiative".
"Ngā Pōtiki are smart and professional leaders who are confident enough to challenge the status quo and negotiate innovative housing solutions with Westpac," he said.
Mason said the shared equity scheme gave the families hope to be able to climb the property ladder and pride in owning their own home.
Tauranga Mortgage Brokers mortgage and finance specialist Tracey Robinson was not familiar with Ngā Pōtiki's initiative but said shared equity was becoming more popular among Tauranga buyers.
Robinson said he would speak with clients about a shared-equity option "once or twice a week". "It is becoming more and more common," he said.
