Common buildings:
Picture
Name
Cost
Requires
Function
Village Hall
nothing
nothing
*The Village Hall is automatically built in every town and produces 500 gold per day.
Town Hall
2500 gold
*Village Hall
*Tavern
*The Town Hall replaces the Village Hall and produces 1000 gold per day.
City Hall
5000 gold
*Town Hall
*Blacksmith
*Mage Guild
*Marketplace
*This improvement upon the Town Hall produces 2000 gold per day.
Capitol
10000 gold
*City Hall
*Castle
*This final upgrade of the previous three buildings produces 4000 gold per day but can only be built in one of your towns.
*When you capture a town with a Capitol while you already have one, the new one is automatically downgraded to a City Hall.
Fort
5000 gold +20 wood +20 ore
*Village Hall
*When a Fort is built, the town is surrounded by walls.
Citadel
2500 gold +5 ore
*Fort
*This improvement upon the Fort adds a moat and an arrow tower to the town's defense.
*Creature growth increases by 50%.
Castle
5000 gold +10 wood +10 ore
*Citadel
*This final upgrade of the previous two buildings adds 2 smaller arrow towers to the town walls.
*The total basic creature growth is increased by 100%.
Mage Guild level 1
2000 gold +5 wood +5 ore
*Village Hall
*The Mage Guild allows heroes to learn 5 level 1 spells.
*Spellbooks can be purchased here for 500 gold.
*The Mage Guild also restores the full amount of spellpoints of any hero that ends his/her turn in that town.
Mage Guild level 2
1000 gold +5 wood +5 ore +4 crystal +4 gems +4 mercury +4 sulfur
*Mage Guild level 1
*This upgrade adds another level to the Mage Guild where heroes can learn 4 level 2 spells.
Mage Guild level 3
1000 gold +5 wood +5 ore +6 crystal +6 gems +6 mercury +6 sulfur
*Mage Guild level 2
*This upgrade adds another level to the Mage Guild where heroes can learn 3 level 3 spells.
Mage Guild level 4
1000 gold +5 wood +5 ore +8 crystal +8 gems +8 mercury +8 sulfur
*Mage Guild level 3
*This upgrade adds another level to the Mage Guild where heroes can learn 2 level 4 spells.
Marketplace
500 gold +5 wood
*Village Hall
*The Marketplace allows you to trade one type of resources for another type. (the rate gets more profitable if you control more Marketplaces)
*You can donate resources to other players here too.
Shipyard
2000 gold +20 wood
*Village Hall
*Enables ships to be build. (1000 gold and 10 wood per ship)
Tavern
500 gold +5 wood
*Village Hall
*In the tavern you can recruit new heroes for 2500 gold each. (the available heroes change every week)
*Your heroes that have fled or surrendered from combat end up in the tavern as well.
*In the tavern you can also listen to rumors.
*You can visit the Thieves' Guild to check on the status of your opponents. (the more taverns you own, the more detailed the information in the Thieves' Guild'll be)
*The tavern also increases the Morale of garissoned troops by 2.


Castle buildings:
Picture
Name
Cost
Requires
Function
Blacksmith
1000 gold +5 wood
*Village Hall
*The ballista can be purchased here.
Brotherhood of the Sword
500 gold +5 wood
*Tavern
*Garissoned troops get Morale +2 during siege combat.
Griffin Bastion
1000 gold
*Griffin Tower
*3 more Griffins/Royal Griffins are available each week.
Lighthouse
2000 gold +10 ore
*Shipyard
*Increases the movement of your ships.
Resource Silo
5000 gold +5 ore
*Marketplace
*Produces 1 wood and 1 ore each day.
Stables
2000 gold +10 wood
*Barracks
*Increases the movement of visiting heroes until the end of the week.


Castle creature buildings:
Picture
Name
Cost
Requires
Function
Guardhouse
500 gold +10 ore
*Fort
*Pikemen are trained here.
Upgraded Guardhouse
1000 gold +5 ore
*Guardhouse
*Halberdiers are trained here.
Archers' Tower
1000 gold +5 wood +5 ore
*Guardhouse
*Archers are trained here.
Upgraded Archers' Tower
1000 gold +5 wood +5 ore
*Archers' Tower
*Marksmen are trained here.
Griffin Tower
1000 gold +5 ore
*Barracks
*Griffins are trained here.
Upgraded Griffin Tower
1000 gold +5 ore
*Griffin Tower
*Royal Griffins are trained here.
Barracks
2000 gold +5 ore
*Guardhouse
*Blacksmith
*Swordsmen are trained here.
Upgraded Barracks
2000 gold +5 ore +5 crystal
*Barracks
*Crusaders are trained here.
Monastery
3000 gold +5 wood +5 ore +2 crystal +2 gems +2 mercury +2 sulfur
*Mage Guild
*Barracks
*Monks are trained here.
Upgraded Monastery
1000 gold +2 wood +2 ore +2 crystal +2 gems +2 mercury +2 sulfur
*Monastery
*Zealots are trained here.
Training Grounds
5000 gold +20 wood
*Stables
*Cavaliers are trained here.
Upgraded Training Grounds
3000 gold +10 wood
*Training Grounds
*Champions are trained here.
Portal of Glory
20000 gold +10 crystal +10 gems +10 mercury +10 sulfur
*Monastery
*Angels are trained here.
Upgraded Portal of Glory
20000 gold +10 crystal +10 gems +10 mercury +10 sulfur
*Portal of Glory
*Archangels are trained here.


The Grail:
Picture
Name
Cost
Requires
Function
Colossus
nothing
*Village Hall
*+5000 gold/day
*+50% creature growth
*All allied heroes get +2 Morale