Reviews from Goodreads:

The Paris Architect-

Like most gentiles in Nazi-occupied Paris, architect Lucien Bernard has little empathy for the Jews. So when a wealthy industrialist offers him a large sum of money to devise secret hiding places for Jews, Lucien struggles with the choice of risking his life for a cause he doesn’t really believe in. Ultimately he can’t resist the challenge and begins designing expertly concealed hiding spaces—behind a painting, within a column, or inside a drainpipe—detecting possibilities invisible to the average eye. But when one of his clever hiding spaces fails horribly and the immense suffering of Jews becomes incredibly personal, he can no longer deny reality.

Written by an expert whose knowledge imbues every page, this story becomes more gripping with every life the architect tries to save.

House of Thieves-

In 1886 New York, a respectable architect shouldn’t have any connection to the notorious gang of thieves and killers that rules the underbelly of the city. But when John Cross’s son racks up an unfathomable gambling debt to Kent’s Gents, Cross must pay it back himself. All he has to do is use his inside knowledge of high society mansions and museums to craft a robbery even the smartest detectives won’t solve. The take better include some cash too —the bigger the payout, the faster this will be over.
With a newfound talent for sniffing out vulnerable and lucrative targets, Cross becomes invaluable to the gang. But Cross’s entire life has become a balancing act, and it will only take one mistake for it all to come crashing down —and for his family to go down too.