How does one say 'because of' or 'on account of' in French?

For example, "The house is very bright because of the large windows". I guess I am looking for 'because of', as in 'on account of'. My next question will be this: If the expression ends in 'de', do I need to combine this with the word that follows to create a new articulated preposition? For example, if the next word is 'le', do I say "du"? I hope that someone can make sense of this. Please do not type my question into a translator. I am looking for people who actually speak French to answer this question. Thanks! Merci!