The Basics
Buildings play an important role in the game, especially during the early stages. Buildings are immune to most skills (the exceptions to this rule are listed below) but are all static, AI-controlled defensive structures.
Buildings grant gold, and thus are a decent source of income if you are able to destroy them. Some buildings, such as Towers, grant the entire team goldm, whereas more minor structures only give gold to the hero that manages to last hit it.
The Exceptions
The following abilities can affect buildings:
Clinkz - Searing Arrows (the bonus damage works on buildings).
Dragon Knight - Level 1 Elder Dragon Form (Corrosive Breath deals the full 20 damage per second to buildings).
Jakiro - Liquid Fire (slows a tower's attack speed).
Naga Siren - Song of the Siren (Naga's sleep affects buildings, which means that enemy buildings cannot attack or be attacked).
Razor - Eye of the Storm (with Aghanim's Scepter).
Tiny - Toss (buildings cannot be targetted by Tiny's Toss, but will take 33% splash damage).
Viper - Nethertoxin (deals 50% damage to buildings).
Death Prophet - Exorcism (Death Prophet's spirits can attack buildings).
Faceless Void - Chronosphere (Chronosphere halts time on both friendly and enemy buildings).
Leshrac - Diabolic Edict (will affect buildings).
Pugna - Nether Blast (deals 33% splash damage to buildings).
Sniper - Shrapnel (deals 33% damage to buildings).
Treant Protector - Living Armor (unique amongst all abilities, Living Armor actually helps buildings by adding health regeneration to a single building).
Glyph of Fortification
The Glyph of Fortification is a team ability which allows any member of the team to make all of the team's buildings invulnerable for 5 seconds.
This ability has a lengthy 5 minute cooldown to compensate for its strong potential impact of the game.
