A seal assembly (176; 276) for a gas turbine engine comprising: a blade outer air seal (BOAS) (169; 269) including a seal body (170; 270) having a sealing portion that extends from an engagement portion (179; 279), the sealing portion including a seal face that extends circumferentially between first and second mate faces (178; 278), the seal body (170; 270) defining an internal cavity (184; 284) that extends circumferentially between the first and second mate faces (178; 278), and the engagement portion (179;279) including an impingement face (189; 289) opposite the seal face (178; 278) that defines a plurality of apertures (191; 291) to the internal cavity (184; 284); and a housing (137; 237) mounted to the blade outer air seal (169; 269) such that the impingement face (189; 289) is exposed to define a plenum (174; 274) between the housing (137; 237) and the impingement face (189; 289), the housing (137; 237) defining a plurality of cooling passages (139; 239), and each of the plurality of cooling passages (139; 239) defining a passage axis that is oriented such that a projection of the passage axis intersects the seal body (170; 270); a mounting block including an interface portion extending from a mounting portion, the interface portion abutting the engagement portion (179; 279) along an interface between the mounting block and the seal body (170; 270) to limit relative movement, and the mounting portion mechanically attached to the housing (137; 237); wherein the internal cavity (184; 284) extends from a first opening along the first mate face (178; 278) to a second opening along the second mate face (178; 278) and the blade outer air seal (169; 269) has a unitary construction; and characterised in that the blade outer air seal (169; 269) is made of a first material including a ceramic material; and in that the mounting block is a first mounting block and a second mounting block, and the interface portion of the first mounting block is received in the first opening and the interface portion of the second mounting block is received in the second opening to secure the blade outer air seal (169; 269) to the housing (137; 237). a blade outer air seal (BOAS) (169; 269) including a seal body (170; 270) having a sealing portion that extends from an engagement portion (179; 279), the sealing portion including a seal face that extends circumferentially between first and second mate faces (178; 278), the seal body (170; 270) defining an internal cavity (184; 284) that extends circumferentially between the first and second mate faces (178; 278), and the engagement portion (179;279) including an impingement face (189; 289) opposite the seal face (178; 278) that defines a plurality of apertures (191; 291) to the internal cavity (184; 284); and a housing (137; 237) mounted to the blade outer air seal (169; 269) such that the impingement face (189; 289) is exposed to define a plenum (174; 274) between the housing (137; 237) and the impingement face (189; 289), the housing (137; 237) defining a plurality of cooling passages (139; 239), and each of the plurality of cooling passages (139; 239) defining a passage axis that is oriented such that a projection of the passage axis intersects the seal body (170; 270); a mounting block including an interface portion extending from a mounting portion, the interface portion abutting the engagement portion (179; 279) along an interface between the mounting block and the seal body (170; 270) to limit relative movement, and the mounting portion mechanically attached to the housing (137; 237); wherein the internal cavity (184; 284) extends from a first opening along the first mate face (178; 278) to a second opening along the second mate face (178; 278) and the blade outer air seal (169; 269) has a unitary construction; and characterised in that the blade outer air seal (169; 269) is made of a first material including a ceramic material; and in that the mounting block is a first mounting block and a second mounting block, and the interface portion of the first mounting block is received in the first opening and the interface portion of the second mounting block is received in the second opening to secure the blade outer air seal (169; 269) to the housing (137; 237).