ToE H5/HoF
Magic Guild level one
Magic Guild level one Cost Requirements Magic Guild level one
  • 2000
  • 5
  • 5
Town Level 3
Effect
Allows a visiting hero to learn the spells kept within. Keeps 3 spells of the first circle.
Magic Guild level two
Magic Guild level two Cost Requirements Magic Guild level two
  • 1000
  • 5
  • 5
  • 1
  • 1
  • 1
  • 1
Town Level 3
Magic Guild level one
Effect
An upgrade of the Magic Guild level one.
Allows a visiting hero to learn the spells kept within. Adds 3 spells of the second circle.
Magic Guild level three
Magic Guild level three Cost Requirements Magic Guild level three
  • 1000
  • 5
  • 5
  • 2
  • 2
  • 2
  • 2
Town Level 3
Magic Guild level two
Effect
An upgrade of the Magic Guild level two.
Allows a visiting hero to learn the spells kept within. Adds 3 spells of the third circle.
Magic Guild level four
Magic Guild level four Cost Requirements Magic Guild level four
  • 1000
  • 5
  • 5
  • 3
  • 3
  • 3
  • 3
Town Level 3
Magic Guild level three
Effect
An upgrade of the Magic Guild level three.
Allows a visiting hero to learn the spells kept within. Adds 2 spells of the fourth circle.
Magic Guild level five
Magic Guild level five Cost Requirements Magic Guild level five
  • 1000
  • 5
  • 5
  • 5
  • 5
  • 5
  • 5
Town Level 3
Magic Guild level four
Effect
An upgrade of the Magic Guild level four.
Allows a visiting hero to learn the spells kept within. Adds 2 spells of the fifth circle.
Training Grounds
Training Grounds Cost Requirements Training Grounds
  • 3500
  • 10
  • 5
  • 5
Town Level 6
Effect
The Training Grounds supports Training special ability, allows to train lower tier troops into higher tier troops (only 7 creatures can be trained in the town with this building per week).
Hall of Heroes
Hall of Heroes Cost Requirements Hall of Heroes
  • 5000
  • 10
  • 5
  • 5
Town Level 9
Training Grounds
Effect
The Hall of Heroes supports Training special ability and allows to train additional 13 creatures per week.
Stables
Stables Cost Requirements Stables
  • 2000
  • 10
  • 5
Town Level 9
Effect
The Stables grants any visiting hero a bonus to his or her movement points until the end of the week.
Farms
Farms Cost Requirements Farms
  • 1000
Town Level 3
Peasant Huts
Effect
The Farms boosts Peasant or Conscript growth by +5 per week.
Elrath's Sentinel
Elrath's Sentinel Cost Requirements Elrath's Sentinel
Effect
Elrath's Sentinel increases weekly creature growth by 50%, provides your empire with an additional 5000 gold each day and boosts luck of all your heroes by +2. A Tear of Asha is required to build this structure.
Expert's Corner (by ThE_HyDrA)

Haven's Special Buildings are rather poor in comparison to the other towns, having only 2 special buildings that are not correlated with their special ability. While the other 2 may be good for the Training ability, the remaining two are sub-par.

The Hall of Heroes is definitely an obligatory purchase, and the inclusion of 5 sulfur does not pose a problem since it's not a primary resource for the Haven.

The Stables is a fairly expensive structure for its effect. While it is a good boost for a week, visiting the castle is the problem, as they are usually tucked away in a corner. Build the Stables only if the castle is on a main causeway, enabling you to make use of the stables as just another adventure map object. If the castle is placed in an unfavourable position, there is little use for the stables, unless you would like to give visiting (adventuring) heroes a headstart on their journeys. (Of course, they're required for the Jousting Arena).

The Farms are not a very good investment, especially in the latter stages. Considering the training ability, the Farms become a little more useful as these surplus level 1 units can be trained into competent fighters. But without this ability, the Farms are not efficient, either. When compared with the Academy's Treasure Cave, which provides it with 2 additional Genies/Master Genies per week and an additional 500 gold per day there is no contest. Admittedly, the Farms cost less, but it only provides an extra 40 Power for Conscripts compared to 160 Power for Djinn Sultans. Only consider buying the farms if you're skilled in the art of Training or after some extra gold.

This information comes from the Heroes V release version (v2.1).

Thanks to Fiur for the in-game screenshots.
Thanks to sfidanza for the work on this page.
Thanks to ThE_HyDrA for creating and looking after the Heroes 5 section of Age of Heroes!