Lapham Rising by Roger Rosenblatt

Harry March is something of a wreck and more than half nuts. Up until now, he has lived peacefully on an island in the Hamptons with his talking dog, Hector, a born-again Evangelical and unapologetic capitalist. But March’s life starts to completely unravel when Lapham—an ostentatious multimillionaire who made his fortune on asparagus tongs—begins construction of a gargantuan mansion just across the way. To Harry, Lapham’s monstrosity-to-be represents the fetid and corrupt excess that has ruined modern civilization. Which means, quite simply, that this is war.