What is the synonym for duplex?

Here are some synonyms for duplex, depending on the context:

General:

* Two-family house

* Two-unit dwelling

* Twin house

* Semi-detached house (if it's attached to another unit)

More specific:

* Multi-family dwelling (if it has more than 2 units)

* Condominium (if it's part of a larger development)

* Apartment (if it's considered a rental unit)

The best synonym will depend on what you're trying to say.