Brothers who have made nearly $1 billion selling luxury property tell us the advantages of working with family

They also happen to be brothers.

Together, they represent the top five most expensive rentals and five of the top ten most expensive properties in the exclusive holiday destination of the Hamptons in Long Island, New York.

"All of our negotiations are based on want, not need," Cody told Business Insider.

"Our average sale is around $25 million (£19 million), and our average listing is around $27 million (£21 million), so we deal in a space that is completely emotional."

The brothers admit they are lucky, because working with a family member isn't always a good idea. Cody said he has seen businesses rip families apart, because for some people, mixing your personal life with your career just doesn't work.

"It takes a very strong team, a communicative team to compartmentalise the segments of their life," Cody said. "When you've seen a lot of people who have been families working together in business, it's not so much the business that collapses, I think it's inequitable portions of how that business gets divvied up, but it's also the personal elements that creep into the business world."

However, he told Business Insider that working with his brother has helped them get ahead in the real estate world. Here's why:

They use their differences to their advantage

Firstly, although the Vichinskys share DNA, they have different personalities, skills, and perspectives, which lends them both to different areas of the business.

"We've mastered the good cop/bad cop by now," Cody. "We definitely have different ways of negotiating a deal, or strategising with a deal, and our personalities are also very different. I'm a little more aggressive, and a little more verbose. My brother is a little more to the point and elegant."

Cody deals with a lot of the buyers and the market intelligence side of the business, whereas Zachary handles the listings and corporate management.

"My brother is a very meticulous, calculated person, and he measures five times before he cuts once, whereas I'm a little more of a quick shooter than he is," he said.

Rather than falling out over their differences, the Vichinskys use them to their advantage. For example, if Cody is struggling to close a deal, Zachary comes in at the end with a different voice.

"We like to say our two brains in one give us the perfect business human," he said. "Our spectrum is completely covered."

They tell it like it is

Zachary and Cody put their success of working together down to being very close. The disadvantages you might encounter, such as arguments about a deal or client, can be mitigated "if you are real with each other, and you have a deep bond with each other."

"There is no pulling of punches. We can speak really authentically, even if it hurts. That's the benefit of having somebody you don't have to be political with," Cody said.

They split everything down the middle

"My brother and I split everything 50/50. There's never an argument over money — money will never come in between us."

In fact, if Cody makes a big sale, he says the first thing he does is give his brother half of the earnings.

"I think that's the fundamental element that often gets in between people in these type of scenarios — it's who's getting what."

The brothers came from a small, tight-knit family, which is the reason Cody gives for having such a close relationship. He says their father used to remind them all the time that all they had was each other, so it was a dream early on to have a business together.

"It's somewhat uncommon to be splitting your life, but we feel that two brains are better than one," he said. "It's a good lesson, and it's a rare one. We often meet a lot of our clients who have brothers or sisters, and they tell us all the time 'I wish we had your relationship.'"