Justin watched Theo carefully as he spoke, seeing that the man missed very little - if anything. He heeded Millicent's advice the whole time, and kept both his eyes and ears open.
He looked up when he asked about finances. "Well," he said with a bit of a wry smile, "my father is in investments - of the muggle kind, of course."
"He made sure that we had a thorough grounding in finance, and when I first started building, he helped invest the business."
"It's not galleons, but the theory is very similar." He didn't know how much Muggle prejudice Nott had, but perhaps money was a universal language that spanned the wizarding/muggle divide.
"But most of the muggle construction work I did was commerical - shopping centres, office buildings, rather than homes." What other experience could he offer?