Landlords specifying cisterns for an HMO refurb usually pick on looks alone, and that's exactly where it goes wrong. A concealed cistern behind a wall panel looks cleaner on day one, but a valve fault two years later can mean opening tiled walls just to reach it, while a close-coupled cistern's mechanism is under the lid in full view. This guide breaks down what each type actually costs to maintain across a multi-bathroom property, when concealed is genuinely worth it, and what Building Regs expect if you do go concealed.