Afik HanahalPenthouse
In short
A true penthouse is the top floor, usually one apartment, with a private roof. Everything else - "mini", "roof duplex" or "roof" - is marketing language worth checking against the permit drawings.
The professional explanation
There is no statutory definition; the permit defines "apartment on floor X" and terrace/roof areas. Check: whether the roof is attached to the apartment in the Tabu, whether there are additional building rights on the roof, and what may be built there (pergola, pool, room).
Pricing: penthouses sell at a premium per m², but the premium applies mainly to built area; terrace area is priced at a lower rate. Roof building deviations (enclosed terraces) are common and complicate sales.
In new Sharon projects the penthouse is usually the most expensive unit, marketed to buyers swapping a detached house for a maintenance-free apartment.
Example from the field
An apartment in Ra'anana was marketed as a "penthouse", but the permit showed an apartment on the floor below the top with a terrace. The difference in value and demand is significant, and a buyer who checked the permit priced accordingly.