Quincy and Karalee Tangiau are the founders of construction company Stronghold Group. For them, success isn't measured in profit alone, but in the social impact they create.
Quincy and Karalee Tangiau measure success differently. For the founders of the Tāmaki Makaurau-based construction company Stronghold Group, it’s not profit margins or turnover that matter most – it’s their impact on people and communities.
In fact, championing the success of their rapidly growing business was so far from their minds that the couple hadn’t even heard of the Deloitte Fast 50 until their bank manager mentioned it.
“We’ve got four companies now, and we’ve been looking at where we want to take them and how we want to grow,” Karalee Tangiau, the managing director of Stronghold Group, said. “One of the things we’re doing is purchasing a commercial property to bring all four businesses under one roof. When we shared our financials with the bank, they said: ‘You should really consider entering the Deloitte Fast 50’.”
Celebrating its 25th year in 2025, the Deloitte Fast 50, which champions businesses turning ambition into revenue and scaling at speed, have featured some of the country’s most recognisable brands over the past quarter of a century.
This year, the Deloitte Fast 50 will again celebrate and rank Aotearoa’s New Zealand’s fastest growing businesses across the Fast 50 and Master of Growth indices.
Regional celebrations announcing this year’s regional category winners and those businesses that have made it to the indices were held across the country last night. During the Auckland event, Stronghold Group was recognised as a Fast 50 finalist and was awarded for winning two Auckland regional categories, the fastest-growing construction business and the fastest-growing Māori- or Pasifika-owned business.
The Tangiaus say Stronghold Group’s success has been built on values that are laser-focused on people: aroha (love and compassion), mahitahi (working together in unity), whanaungatanga (connection and relationships) and manaakitanga (care and respect).
Today, 85% of Stronghold Group’s staff are Māori or Pasifika and the company invests 35% of its subcontracting spend in other Māori- and Pasifika-owned businesses.
Quincy Tangiau, who has heritage from the Cook Islands, Niue and Papua New Guinea, began his construction journey through a scholarship carpentry course for Māori and Pasifika students. Years later, he returned as a tutor, a full-circle moment that marked the beginning of a deeper purpose: to give back.
Karalee Tangiau, of Ngāti Whātua ki Kaipara descent, has dedicated over 21 years to early childhood and tertiary education. Her career was grounded in ensuring every student could reach their full potential.
In 2017, Quincy and Karalee Tangiau attended a Tony Robbins Unleash the Power Within seminar alongside friends, all seeking inspiration to do more. It became a defining moment that ignited their belief that they could do more. Several years of planning, learning, and perseverance later, Stronghold Group was born in 2020.
“Karalee leads the systems and process side of the business with her team of incredible wāhine – they are our backbone, the foundation that held everything together,” Quincy Tangiau, the operations manager, said. “They set up the paperwork, proposals, insurances and health and safety systems, and because of that, we went from zero to a hundred, fast. It opened the door for us to tender for larger projects with Government, council and iwi, while continuing to collaborate with many tier-one and tier-two construction companies.”
Commenting on the duo, Karalee Tangiau said: “Quincy is known for his strategic thinking and willingness to take calculated risks, he has been instrumental in driving innovation across the business, making him a driving force behind the creation of our other companies and recognising gaps in the market where we could make a genuine impact that add value to the construction industry.”
Stronghold Group’s initial focus was on smaller projects and maintenance, such as exhibitions at the Museum of Transport and Technology (Motat). It now works on a wide range of projects, from residential and commercial builds, council and government work with the likes of Auckland Council, the Ministry of Education and Health New Zealand Te Whatu Ora to culturally significant works across marae and maunga.
Both Karalee and Quincy Tangiau attribute the phenomenal growth to pursuing opportunities, calculated risks, and investing in people and relationships. For them, success isn’t measured in profit alone, but in the social impact they create.
Education remains central to their kaupapa. The pair prioritise upskilling and career progression for their team and even facilitate life skills workshops on topics such as KiwiSaver, first-home ownership and financial wellbeing.
“We knew we had the ability to be the change we wanted to see, so we’ve always been driven by that,” Karalee Tangiau said.
As Stronghold Group looks to the future, the couple are preparing to expand their impact further, including developing opportunities in Rarotonga to create pathways into construction for local communities.
The Deloitte Fast 50 national winner and the full indices of ranked companies will be announced on November 27, 2025 at a celebration event in Auckland. The Fast 50 regional category winners can be viewed online now.