Is the word casas the same in Brazilian and European Portuguese?

Yes.

The spelling, meaning, and grammatical function of "casas" (the plural of casa, meaning "houses" or "homes") are identical in both Brazilian and Continental Portuguese. The only difference lies in pronunciation:

• In Brazilian Portuguese, the "s" at the end of the word is typically pronounced as a sibilant /s/ (like the "s" in "sun").
• In Continental Portuguese, the "s" at the end of the word is typically pronounced as a postalveolar fricative /ʃ/ (like the "sh" in "she").

Brazilian Portuguese Examples

1. As casas dessa rua são muito bonitas. (The houses on this street are very beautiful.)
2. Ele comprou duas casas no litoral. (He bought two houses on the coast.)
3. As casas de madeira são muito legais. (The wooden houses are very cool.)
4. Tem muitas casas abandonadas por aqui. (There are many abandoned houses around here.)
5. As casas de praia são muito frescas. (Beach houses are very cool.)

Continental Portuguese Examples

1. As casas desta rua são muito bonitas. (The houses on this street are very beautiful.)
2. Ele comprou duas casas no litoral. (He bought two houses on the coast.)
3. As casas de madeira são muito giras. (The wooden houses are very pretty.)
4. Há muitas casas abandonadas por aqui. (There are many abandoned houses around here.)
5. As casas de praia são muito frescas. (Beach houses are very cool.)