Stuart Rattle, who designed the homes of many high-profile Melbourne families was found dead in his South Yarra home in the early hours of Monday morning.

Police are investigating the circumstances surrounding the unit fire on Malvern Road but do not believe it is suspicious.

Veteran landscape gardener Paul Bangay paid tribute to Mr Rattle, 53, describing him as an "incredible" and "passionate" designer.

Mr Bangay and Mr Rattle collaborated on dozens of projects over the years.

"He was just incredible. He had such great style and flair and I could always rely on his great judgment," Mr Bangay said.

"It's a very sad day for us. We were great buddies straight out of uni. We supported each other and learnt from each other and he was just one of my best design buddies and best friends."

Mr Rattle resided in South Yarra and at a farm at Musk just outside Daylesford.

He held an open day at the farm in late November to raise money for The Wombat Hill Botanical Gardens in Daylesford which raised tens of thousands of dollars to secure the future of the gardens.

"He believed in the community and restoring those botanic gardens," Mr Bangay said. "He was just so passionate and will be greatly missed."

Mr Rattle was best known for his classic, timeless designs and his clever use of colour.