"Not many players can earn enough to get away with it after they finish," he says.
"There was an opportunity to get into MIT (Manukau Institute of Technology) back when I played for Auckland, so I did a bit of study during winters when I wasn't playing, and now I'm trying to carry on what I started."
De Grandhomme says the course normally takes three to four years with exams, followed by an apprenticeship. If the coronavirus had not yorked cricket in all its forms, he would've missed New Zealand's mid-year scheduled tours regardless.
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He has quickly learned how to take guard on the job, because even someone of his power is no match for the national grid.
"You've got your testers to make sure it's off, so you don't get zapped," de Grandhomme explains.
"I started in commercial, which was quite tough doing the same thing every day, but houses seem to offer more variety and are more enjoyable. In other winters at home I was mainly helping pre-wire new builds."
The decision to pursue a trade comes as no surprise after he emigrated from Zimbabwe as an 18-year-old in January 2005.
As he told the Herald on Sunday in July 2010: "I didn't know what to do after school so I came to New Zealand for half a season. When that finished, I knew I wanted to come again.
"Fortunately it has worked, because nothing was guaranteed [in Zimbabwe]. I probably would have done a building or mechanic apprenticeship.
"I've never really fancied writing essays."
De Grandhomme might also need to find a renewable energy source on the job in the coming weeks. He and his partner became parents to daughter Lily last month.