How do we know that Bruno's family is rich

Answer:Bruno's family is indeed quite well off. We know this because they live in a palatial, five-story house in an exclusive suburb of Berlin. The house has large windows with extensive views, as well as ornamental features like elegant bannisters. The family also employs a number of servants to attend to their every need, such as Lars the butler and Maria the maid. One would certainly need a substantial disposable income to be able to afford such staff.