"Je vais transformer ma maison en un palais."

Translation: I am going to transform my house in a palace.

[vizen]

INTO a palace

[Sitesurf]

In French, I would skip the indefinite article: je vais transformer ma maison en palais.

[Natka01]

Why?

[Sitesurf]

"en" is very versatile, it does not only mean "in" but it also contains an article, like "je vais en Italie" (lit. à la), or "repose en paix" (lit. dans la), "j'y vais en voiture" (lit. dans une).

It is probably the only preposition that does not always require an article.

[DuolingoUser111]

Just seems more natural that way. Same as you might say 'Je suis avocat' when talking about your profession.

[lpacker]

The way they have this sentence, it sounds like somebody is going to have their house inside of a palace and then transform it into an unspecified "something".

[frogarms]

He is going to take his house INTO a palace (somehow) and them transform form it.