�Hola!
Yes, we also have those concepts (countable and uncountable nouns) in Spanish. It works a little bit different in Spanish.
These link offers information about it:
LearnPlus - About Spanish nouns What happens is that Spanish uncountable nouns can take articles, depending on their meaning or function in the sentence.
I'm thinking right now... when the uncountable noun works as the subject in the sentence, it usually get the article, i.e.:
"El amor es bello" // "No quiero sentir amor"
First sentence: "el amor" works as the subject in the sentence.
Second one: "amor" works as Direct Object.
This is the explanation I can give you so far, but I'll try to retrieve more concrete info about this. Sounds interesting!
About writing "la Casa Blanca" instead of "la casa blanca", as we are talking to an official place or institution, I think we should use capital letters. It's similar to "El Palacio de la Moncloa" (The Palace of La Moncloa) in Madrid.
Hope this helps until I can have more concrete information.
Thanks!