A mansard roof has a few other determining characteristics. For example, they have the tendency to have dormers, or windows that project out from the roof.
Kevin - I could see some of these for extra space and additional light in our master suite. Cape Cod Bathroom Extension to make more functional and spacious. Gable Roof Dormer Addition and Expansion
Dormer Style Ideas: Shed Dormer Windows Give spaces beneath steep rooflines added headroom, light and charm with the addition of a shed dormer window.
Inviting Entry with a Dormer Window, front of house remodel