Father-of-three Dean Wyllie (52) - who helped redevelop London's Waterloo Station - was the architect on Prime TV's The Kiwi Dream renovation show.
He was found dead on Friday by his brother Fraser after having fallen down external stairs to his Epsom home that morning.
Yesterday, his brother said the family were devastated by the loss of the "very social, gregarious" architect, who is survived by twin 17-year-old sons and a 13-year-old daughter.
"It looks like he has fallen down the steps at his house. We're not sure if it's a heart attack or he's just slipped," Fraser Wyllie said. "A neighbour alerted me and I found him."
His death had been referred to the coroner.
A graduate of Victoria University in Wellington, Mr Wyllie worked in Moscow, the Pacific Islands and London - where he led a team redeveloping Waterloo Station in 1993. He returned to New Zealand in the mid-1990s and set up his own business in Auckland.
"It's just tragic," his brother said. "He was larger than life if you met him, you wouldn't forget. He looked after everyone, he was so caring. He was a pretty special guy."
He was the architect on Prime's The Kiwi Dream, a Grand Designs-style makeover show featuring the renovation of a million-dollar cliff-top Glendowie home.
The Kiwi Dream host Evie Ashton said she was "absolutely shocked and saddened" by news of Mr Wyllie's death.
"Dean was a very talented, lovable guy who adored his kids and was a pleasure to laugh and work with," she said.
Geoff Burton, a director at MWC Media, which produced the show, paid tribute to his "dearly treasured friend" on Facebook over the weekend.
"Not only was Dean a highly talented architect but he was also an amazing dad to three very special children, who he loved so deeply."
His death would "leave a void and ache in our hearts that is almost unbearable", Mr Burton said.
"You have been the greatest friend I could have and my life is so much the richer for your input. ... Words cannot describe how much you will be missed."
Mr Wylie's funeral will be held tomorrow at 2pm at C3 Church in Ellerslie.
Dean Wyllie
*Successful architect who graduated from Victoria University.
*Began his career in New Zealand before working in London, Moscow and the Pacific Islands.
*Led the design team on London's Waterloo Station Development in 1993 for the Channel Tunnel train service.
*Returned to New Zealand and started his own practice, Wyllie Architects, in Auckland in the mid-1990s.
*Worked as reality television architect on Prime TV's The Kiwi Dream show, hosted by Evie Ashton.
