Maisonette and Penthouse

Maisonette noun - A self-contained apartment (usually on two floors) in a larger house and with its own entrance from the outside.

Penthouse and maisonette are semantically related. In some cases you can use "Penthouse" instead a noun "Maisonette".

Penthouse noun - A smaller structure added to a main building.

Maisonette and penthouse are semantically related. You can use "Maisonette" instead a noun "Penthouse".