StarCraft/Zerg buildings

Hatchery / Lair / Hive
The Hatchery is the Zerg's primary building. It is where gathered resources are dropped off. Unlike the other races, the Hatchery is where all Zerg units spawn. The Hatchery also can be upgraded, opening up the tech tree each time. The first upgrade changes it to a Lair, the second to a Hive. At the Hatchery level, Burrow can be researched, and at the Lair level, Overlord Transport, Speed, and Sight can be upgraded.
 * Cost: 300/0
 * Hotkey: H
 * Available Upgrades
 * Burrow: 100/100
 * Ventral Sacs (Overlord transportation): 200/200, requires Lair
 * Pneumatized Carapace (Overlord speed): 150/150, requires Lair
 * Evolve Antennae (Overlord sight range): 150/150 requires Lair

Extractor
This building allows Drones to collect Vespene Gas, which is needed to build almost every unit. Like its Terran and Protoss counterparts (the Refinery and Assimilator), only one Drone can be inside it at any given time.
 * Cost: 50/0
 * Hotkey: E

Spawning Pool
The Spawning Pool is required to create Zerglings and opens up the rest of the tech tree. Two Zergling-specific upgrades can be researched here. The second upgrade cannot be initiated until the Hatchery has been evolved into a Hive.
 * Cost: 200/0 (originally 150/0, adjusted in Update 1.08)
 * Hotkey: S
 * Available Upgrades
 * Metabolic Boost (increases Zergling speed): 100/100
 * Adrenal Glands (increases Zergling rate of attack): 200/200, requires Hive

Hydralisk Den
The Hydralisk Den, as its name suggests, allows the production and support of Hydralisks. Dedicated (like most Zerg buildings) to a unit, it allows two Hydralisk-specific upgrades in StarCraft and a third one in the Brood War expansion. Both basic upgrades (speed and range) are quite useful, as the Hydralisk is considered by most to be the backbone unit of the Zerg forces. The Brood War-only upgrade is the Lurker aspect evolution, which allows the Hydralisk to go back into its egg form and re-emerge as a Lurker.
 * Cost: 100/50
 * Hotkey: D
 * Available Upgrades
 * Leg Enhancements(Increases Hydralisk movement speed): 150/150
 * Grooved Spines(Greater Hydralisk attack range): 150/150
 * Lurker Aspect (allows Hydralisks to morph into Lurkers): 200/200, requires Lair, Brood War only

Evolution Chamber
The Zerg ground unit upgrades can be found here. They are: carapace, melee attacks, and ranged attacks. The second levels of each upgrade can only be achieved with a Lair, and the third levels can only be researched with a Hive.
 * Cost: 75/0
 * Hotkey: V
 * Available Upgrades
 * Upgrade Melee Attacks (Zergling, Broodling, and Ultralisk attacks): Level 1: 100/100, Level 2: 175/175, Level 3: 250/250
 * Upgrade Missile Attacks (Hydralisk and Drone attacks): Level 1: 100/100, Level 2: 175/175, Level 3: 250/250
 * Upgrade Carapace (all ground units receive armor): Level 1: 150/150, Level 2: 225/225, Level 3: 300/300

Creep Colony
This building extends the Creep as to give more room for buildings. The Creep Colony can be mutated into a Sunken or Spore colony for defense purposes.
 * Cost: 75/0
 * Hotkey: C

Sunken Colony
Mutated from a Creep Colony. It is the strongest ground defense of any race, dealing 40 explosive damage to any nearbly enemy ground units.
 * Cost: 50/0
 * Prerequisites: Creep Colony, Spawning Pool
 * Hotkey: U

Spore Colony
Mutated from a Creep Colony. It is the sturdiest air defense of any species, with 400 hit points. Its damage of 15, however, make this building not as effective at its job as the Sunken Colony.
 * Cost: 50/0
 * Prerequisites: Creep Colony, Evolution Chamber
 * Hotkey: S

Queen's Nest
This building allows for production of Queens. Also, Queen abilities and upgrades such as Ensnare, Spawn Broodlings, and greater energy capacity can be evolved here. Finally, it is the prerequisite for Hives.
 * Cost: 150/100
 * Hotkey: Q
 * Prerequisite: Lair
 * Available Upgrades
 * Ensnare (Queen ability): 100/100
 * Spawn Broodling (Queen ability): 100/100
 * Gamete Synthesis (increased Queen energy): 150/150

Spire
One of the more important Zerg structures, the Spire allows production of basic air units at the Hatchery. Also, air unit weapons and armor can be upgraded here. This structure can be upgraded into a Greater Spire. The third levels of both air unit upgrades require the upgraded form.
 * Cost: 200/150
 * Hotkey: S
 * Prerequisite: Lair
 * Available Upgrades
 * Upgrade Flyer Attacks: Level 1: 100/100, Level 2: 175/175, Level 3: 250/250
 * Upgrade Flyer Carapace: Level 1: 150/150, Level 2: 225/225, Level 3: 300/300

Greater Spire
The mutation of Mutalisks into Guardians and Devourers and the final levels of air upgrades require this structure.
 * Cost: 100/150 (in addition to the Spire's cost)
 * Hotkey: G
 * Prerequisite: Spire, Hive.

Defiler Mound
Allows for production of Defiler. Also allows Consume, Plague, and greater energy capacity to be evolved.
 * Cost: 100/100
 * Hotkey: D
 * Prerequisite: Hive
 * Consume: 100/100
 * Plague: 150/150
 * Metasynaptic Node: 150/150

Ultralisk Cavern
Allows for production of Ultralisk. Allows evolution of Armor and Speed.
 * Cost: 150/200
 * Hotkey: U
 * Prerequisite: Hive
 * Anabolic Synthesis(Speed):150/150
 * Chitnous Plating(thicker carapace):150/150

Nydus Canal
Allows units to move from one place to another quickly. Once built, an exit node can be placed, but exit node must be on creep.
 * Cost: 150/0
 * Hotkey: N
 * Prerequisite: Hive