Archon,Upgrade Sketches can be used to upgrade certain buildings in your City, increasing their bonuses and making them even more powerful!

And with Upgrade Sketches, comes further updates: now you can upgrade your Buildings to even higher Levels! Each new Level brings even greater bonuses.

Upgrade Sketches can be used to upgrade:

Lumberyards;

Forges;

Farms;

Granaries;

Warehouses;

The Temple of Hephaestus;

The Agora;

The Acropolis;

The Infirmary;

The Port;

The Harbor;

The Lighthouse.

for example, when you reach level 20 in your Granaries; , you will have to use the schemes, to improve the level 25 and among other buildings