Not when they are qualifying a noun, like in this sentence. Think of nagy épületeket as one grammatical unit, which only needs to take the accusative (and the plural) suffix once - on the noun at the end.
If the adjective is standing alone, behaving as a noun itself rather than modifying some other noun, then it will take any endings that a noun would take in the same place.
Hol látsz sárga búszokat? - Where do you see yellow buses?
Hol látsz sárgákat? - Where do you see yellow ones / yellow things?
I think this particular sentence could also report "tall" buildings as a correct translation.
"Tall" would be signified specifically by "magas" rather than the more general "nagy."
For me this was a "select the correct English words from a list" type question and my answer had to be "Where can I see large buildings?" My question is this - is there no difference in Hungarian for doing something (Where do I see...) and being able to do something (Where can I see...). Does this come later?
With a few verbs, there is no need for a separate verb to express can - most commonly lát (see), hall (hear), and talál (find). So, lát means "see" or "can see", and hall means "hear" or "can hear".
Nem látok semmit - "I don't see anything" or "I can't see anything" (and when you think about it, there's not much actual difference in meaning between those two sentences, so you can kind of see why Hungarian doesn't bother to distinguish between them).
In general, there are a few ways of expressing the idea of "can" in Hungarian via helping verbs or suffixes but I think the only way that comes up in the Duo course is the helping verb tud.