"Το μέγιστο σπίτι."

[DinaKont]

το μεγαλύτερο instead of το μεγιστο is much more frequently used, so I think it should be included

[gioan777]

For the life of me I've never heard anyone using το μέγιστο in Greece in order to say "the biggest" in the context of size. A more accurate translation would be "the maximum".

[fotiosgaridis]

You're right... I added this too. Thanks!

[Stergi3]

Μέγιστος, ancient form. Not used unless you want to speak very formally

[JamesL629559]

We are trying to learn new words so it is good.

[chrisoxe]

the biggest home (σπιτι can be both house but also home as far as I know), would be good to add the choice I think

[fotiosgaridis]

I added this. Thanks for your comment!

[YPSILONZ]

Unlucky choice of words... Nobody would say that in real life.