Hi, welcome to the forum. :drink:
Brewing in the attic has it's challenges.
Ideally you want acess to water and waste plumbing as lots of things need washing, and carrying buckets of water up a ladder is not ideal. I suppose this depends on what the access is like to your attic.
The other challenge is temperature. Yeast is quite fussy, and in order to ferment beer you need to keep it happy, and that means maintaining a temp of between 18 and 22 degrees centigrade, give or take a couple. Attics tend to be very hot or very cold.
There are ways around temperature control by converting a fridge, but would you get a fridge in your attic?
If you are planning to brew All Grain, or extract you have an added problem of the amount of steam that is produced during the boil, you would need some form of extractor.