The word "shantier" does not exist in the English language, so it is impossible to provide antonyms for it. However, assuming you meant "shanty," which refers to a small, poorly built dwelling, some antonyms include mansion, villa, palace, or estate. These words refer to large, elegant homes that are structurally sound and typically owned by wealthy individuals or families. Other antonyms could include apartment, townhouse, or condominium, which are types of multi-unit residential buildings that are typically more modern, spacious, and comfortable than shanties. Ultimately, the antonym for shanty would depend on the context and specific connotations of the original word.