"When I first encountered Zaha's work as a young student in Stuttgart University in the mid 80s it was like a shock of revelation," he wrote. "There was nothing like this. The bounds of architectural possibilities had shifted."
Hadid died in Miami at the age of 65 after suffering a heart attack while in hospital being treated for pneumonia. She was one of the world's most celebrated and divisive architects.
"Zaha had delivered an unprecedented expansion of the discipline's repertoire, offering new degrees of freedom to the designer," wrote Schumacher of his earliest encounters with Hadid's work.
"What we did not yet grasp at the time – and I doubt that Zaha herself or anybody else fully understood this at the time – is the performative empowerment that these new options and degrees of freedom delivered to us as problem solvers: Zaha had expanded architecture's universe of possibilities."
Schumacher said that Hadid had developed a new architectural language with techniques or "moves" that might have previously seemed "surreal or absurd", and titled his tribute Zaha's Incredible Moves.
Perhaps the most important of these was treating her rapidly produced, curved sketches as literal drawings of a building, rather than as ideas or "an ideal geometric form, which was meant to be rationalised into straight lines and arcs".
"A new language of architecture with a much increased problem-solving versatility, and with a much richer, more expressive and more communicative repertoire of organisation and articulation was born," said Schumacher.
He also said Hadid had created a new type of architectural image making, with multiple perspectives that created a depth later achieved and mimicked using computers. And he credited the architect with introducing "gradients" into architectural form-making.
Schumacher, who is one of the champions of Parametricism – a style of architecture that creates organic forms from computer algorithms and programs – said that her work had created new ways of thinking about and designing architectural spaces.
"She was part of a mini-rebellion against the prevailing early 70s ethos in architectural education when many students did not really draw or design but talked instead of megastructural systems and processes, alternative lifestyles and so on," he told Dezeen. "Zaha and her friends went to Alvin and demanded to draw architecture, and Alvin set them up with an independent studio. I guess the die was cast from that point."
Schumacher became a partner at ZHA in 2002, and had been Hadid's co-director and senior designer in the years before her death.