I used to feel your pain, but i solved my own problem with it, maybe this will work for you as well. Go to your C:\Users\Username\Documents\My Games\FallenEnchantress\Mods directory and create a text file using notepad, and copy paste this into it. Then, save as " CoreBuildings.xml "
This is a "modlet" that adds one building for food, one for materials, one for essence. These buildings are nice and cheap, inspired by the building "Scrying Pool". Personally, i copy-pasted the snaking mod info into this file as well! If you want them cheaper, you can reduce the <LaborToBuild> cost. There is a little more advice below this copy-paste textwall.
<ImprovementTypes>
<DataChecksum NoParse="1">
<Ignore>DisplayName</Ignore>
<Translate>DisplayName</Translate>
</DataChecksum>
<ImprovementType InternalName="ShamansHut">
<DisplayName>Shaman's Hut</DisplayName>
<Description>Shaman's Hut increases the Essence yields of any city they are built in.</Description>
<RequiresCity>1</RequiresCity>
<BarredTerrain>River</BarredTerrain>
<BarredTerrain>SwampTerrain</BarredTerrain>
<PreferredTerrain>City</PreferredTerrain>
<PreferredTerrain>Category:Land</PreferredTerrain>
<PreferredTerrain>Forest</PreferredTerrain>
<LaborToBuild>120</LaborToBuild>
<GameModifier>
<ModType>Resource</ModType>
<Attribute>TileYieldEssence</Attribute>
<Value>1</Value>
<PerTurn>1</PerTurn>
<Provides>+1 Essence</Provides>
</GameModifier>
<AIData AIPersonality="AI_General">
<AIPriority>20</AIPriority>
<AITag>Study</AITag>
</AIData>
<ArtDef>Art_ScryingPool</ArtDef>
</ImprovementType>
<ImprovementType InternalName="HarvestFestival">
<DisplayName>Harvest Festival</DisplayName>
<Description>Harvest Festivals increase the Grain yields of any city they are built in.</Description>
<RequiresCity>1</RequiresCity>
<BarredTerrain>River</BarredTerrain>
<BarredTerrain>SwampTerrain</BarredTerrain>
<PreferredTerrain>City</PreferredTerrain>
<PreferredTerrain>Category:Land</PreferredTerrain>
<PreferredTerrain>Forest</PreferredTerrain>
<LaborToBuild>120</LaborToBuild>
<GameModifier>
<ModType>Resource</ModType>
<Attribute>TileYieldGrain</Attribute>
<Value>1</Value>
<PerTurn>1</PerTurn>
<Provides>+1 Grain</Provides>
</GameModifier>
<AIData AIPersonality="AI_General">
<AIPriority>20</AIPriority>
<AITag>Study</AITag>
</AIData>
<ArtDef>Art_ScryingPool</ArtDef>
</ImprovementType>
<ImprovementType InternalName="Toolworker">
<DisplayName>Toolworker</DisplayName>
<Description>Toolworkers increase the Material yields of any city they are built in.</Description>
<RequiresCity>1</RequiresCity>
<BarredTerrain>River</BarredTerrain>
<BarredTerrain>SwampTerrain</BarredTerrain>
<PreferredTerrain>City</PreferredTerrain>
<PreferredTerrain>Category:Land</PreferredTerrain>
<PreferredTerrain>Forest</PreferredTerrain>
<LaborToBuild>120</LaborToBuild>
<GameModifier>
<ModType>Resource</ModType>
<Attribute>TileYieldMaterials</Attribute>
<Value>1</Value>
<PerTurn>1</PerTurn>
<Provides>+1 Materials</Provides>
</GameModifier>
<AIData AIPersonality="AI_General">
<AIPriority>20</AIPriority>
<AITag>Study</AITag>
</AIData>
<ArtDef>Art_ScryingPool</ArtDef>
</ImprovementType>
<ImprovementType InternalName="CrystalChamber">
<DisplayName>Crystaline Chamber</DisplayName>
<Description>Crystaline Chambers increase the number of Crystals in a city they are built in.</Description>
<RequiresCity>1</RequiresCity>
<BarredTerrain>River</BarredTerrain>
<BarredTerrain>SwampTerrain</BarredTerrain>
<PreferredTerrain>City</PreferredTerrain>
<PreferredTerrain>Category:Land</PreferredTerrain>
<PreferredTerrain>Forest</PreferredTerrain>
<LaborToBuild>120</LaborToBuild>
<ModType>Resource</ModType>
<Attribute>RefinedCrystal</Attribute>
<Value>0.25</Value>
<PerTurn>1</PerTurn>
<Provides>+0.25 Crystal per Season</Provides>
<AIData AIPersonality="AI_General">
<AIPriority>20</AIPriority>
<AITag>Study</AITag>
</AIData>
<ArtDef>Art_ScryingPool</ArtDef>
</ImprovementType>
<ImprovementTypes>
You can give a prerequisite to prevent them from being open from the beginning, i chose no prerequisites. To add one, just do this.
<Prereq>
<Type>RestrictedAbilityBonusOption</Type>
<Attribute>Binding</Attribute>
<Target>Player</Target>
</Prereq>
Type tells you that you must have an ability.
Attribute tells you this ability must be the ability "Binding". You can make it Enchanters, WarriorsTech or anything else. In fact, you can do this as well.
<Prereq>
<Type>Resource</Type>
<Attribute>TileYieldEssence</Attribute>
</Prereq>
<Prereq>
<Type>Tech</Type>
<Attribute>Sorcery</Attribute>
</Prereq>
<Prereq>
<Type>Allegiance</Type>
<Attribute>Empire</Attribute>
</Prereq>
<Prereq>
<Type>AbilityBonusOption</Type>
<Attribute>LegacyOfSerrane</Attribute>
<Target>Player</Target>
</Prereq>
The first prerequisite here demands your city already have one essence. Likewise, you can use the second one to tie these buildings to a tech. The third one makes it Empire (or kingdom) only! A fourth makes you require legacy of Serrane ability. You can also change it to CivicsTech.
RestrictedAbilityBonusOption is used to make something ONLY unlock at this tech, such as the mana temples and shrines. While AbilityBonusOption calls on an alternative version, such as Resoln Temples. Whether or not you knew it, Resoln has different temples, and AbilityBonusOption lets this happen. Look, i won't tell you what to do with them! Your game, your fun. Use them how you want, make it give 3 essence and leave it open, you can tie them to techs, or empire/kingdom or you can even add them to a tech.
I know, i know. You didn't ask for code, and you don't want to go around tinkering with this stuff. As is, the code will simply add 3 buildings with no prerequisites. This is my effort to give you a "Copy-Paste" solution to your problem, and i hope it helps. I know i can't live without it!