Is T. knowledgeable about architecture in "The Destructors" by Graham Greene?
Yes, Trevor is knowledgeable about architecture, which is probably why he is so jealous of Old Misery and his surviving house. The exposition makes it clear that Trevor's father was an architect, so some of that knowledge trickled down to Trevor.
First of all, Trevor knows of the builder of the house, Wren, and knows that he is the same builder who built St. Paul's. None of the other boys has any idea what he is talking about. Next Trevor asks Old Misery to tour his home. This request would be odd for a teenage boy if he had no interest in or knowledge of architecture.
Trevor devises the plan to destroy the house, assigns the tools to bring, and assembles a plan that will gut the inside of the house without affecting the appearance of the outside.
"...By six the superficial damage was completed. The doors were all off, all the skirtings raised, the furniture pillaged and ripped and smashed—no one could have slept in the house except on a bed of broken plaster."
Destroying the inside without giving a clue to that destruction on the outside is quite a feat.
This job seems way out of the league of a typical teenage boy with no knowledge of architecture.