Accents for demonstrative pronouns: optional/regional/outdated?

Question

I've been reading a book in print and they have "este" (no accent) as the demonstrative adjective and "éste" (accent) as the demonstrative pronoun:

esta casa (adj.)
ésta es mi casa (pron.)

But I don't see that in this lesson. Is it out of date/RAE stuff or is it only included when ambiguous and my book is being overzealous?

Also, there was a really cool little fact in the book that said that "aquél" and "éste" are used in the same way that "former" and "latter" are in English. I'm still confused as to whether the accent is necessary or optional for pronouns, however.

Answer

Hola J
Until 2010 this was the case: the demonstratives este, ese, aquel took the accent when these were pronouns, not adjectives, but in 2010 RAE decided the written accent wasn't necessary and whichever their function is they do not take the accent. 
Saludos
Inma