"It runs through the blood and I just love the industry. I love helping people most of all," he said.
"You get to see families grow and overall it's just a really, really fun experience getting to know people and getting to help people in some really different situations."
Collett started working in property management at his dad's business - Ray White Glenfield - at 17, but always wanted to start his own company and was a licensed agent.
"There was a little bit of perception in my old workplace that everything was just given to me, which I really, really didn't like," Collett told the Herald on Sunday.
"That's actually part of the reason why I wanted to open up my own franchise - so that people can see that I've worked hard for what I'm doing and with a lot of hard work and dedication you get results."
He employs six staff, aged 25 to 52, and although he'd like to see more young people working in real estate, Collett said he valued trustworthiness above age and previous work experience.
"Honestly, your core values are the only thing you can stick by - and your word."
He said some doubted him because of his youth when he first started in real estate, but his work ethic and values had quickly given him a good name in the industry.
"One challenge I have is sometimes I have a meeting with people and because of my age they look at me as a younger person and don't take me seriously.
"But it's certainly nothing I can't handle."
His business, which provides property management and residential sales services on Auckland's North Shore, aims to improve service and transparency in the real estate industry.
"I don't think [most] agents give property vendors and buyers enough respect for what they do," Collett said.
The market was changing and agents needed to focus on meeting buyers' needs better, he told the Herald on Sunday.
"The buyers are the ones that we need to look after in order to get the sale through. I don't think all salespeople actually know how to deal with buyers because a lot of salespeople for the past couple of years have only ever had to chase listings, so the buyers come running.
"We need to stop just thinking about the listing, we need to start thinking about everybody involved in the transaction and give them all the same service and level of service.
"We're the mediator in the middle trying to find the deal."
Although he was yet to own a home himself and was instead focusing on building up other investments, he'd sold houses to 23-year-olds and said it was possible for young people to get on the property ladder if they developed the right saving habits.
Liam's top five tips for first home buyers
• Buy out of Auckland where it's more affordable, or buy on the outskirts of the city
• Evaluate what is really important to you when spending/saving money
• Draw on the guidance and knowledge of family who've bought property before
• Make sure you get all the right checks done and do your due diligence
• If you're going to rent your property out, get a property manager. Too many landlords who manage rentals themselves miss signs of tenants' drug use because they lack the knowledge.
