Effect · every source

How to reduce Building Construction Cost in CK3

1 source raises Building Construction Cost and 29 lower it in the game files of patch 1.20.0.3 — for this one, lower is better.

build_gold_cost

In Crusader Kings III, 1 source raise Building Construction Cost and 29 sources lower it. Biggest cuts: Watermills -30%, Royal Armories -20%, Ruins of the Palace of Ctesiphon -20%, Manor Reform -15% and Great Mosque of Djenne -15%. It goes up with Industrious +15%. Patch 1.20.0.3, from the modifiers of traits, perks, traditions, buildings and the rest of game/common.

The biggest reductions

-30%WatermillsBuilding · Province
-20%Royal ArmoriesBuilding · Each de jure county of the duchy · culture with Metalworkers
-20%Ruins of the Palace of CtesiphonBuilding · County

What lowers Building Construction Cost (29)

Traits (1)

Architect-10%
architect · game/common/traits/00_traits.txt

Lifestyle perks (1)

Cutting Costs-5%
Not Adventurer government
cutting_corners_perk · game/common/lifestyle_perks/00_stewardship_2_domain_tree_perks.txt

Cultural traditions (1)

Expert Artisans-5%
Counties of this culture
tradition_artisans · game/common/culture/traditions/00_societal_traditions.txt

Culture pillars (1)

Communal-5%
Provinces of this culture
ethos_communal · game/common/culture/pillars/00_ethos.txt

Tenets (1)

Communal Possessions-10%
Followers
tenet_communal_possessions · game/common/religion/tenet_types/00_tenet_types.txt

Holy sites (6)

Nakkavaram-10%
Nakkavaram · Followers, while the faith holds it
nakkavaram · game/common/religion/faith_types/00_faith_types.txt
Nok Kundi-10%
Riqan · Followers, while the faith holds it
nok_kundi · game/common/religion/faith_types/00_faith_types.txt
Nakkavaram-5%
Nakkavaram · Holder of the county
nakkavaram · game/common/religion/faith_types/00_faith_types.txt
Yijinai-5%
Tongcheng · Followers, while the faith holds it
yijinai · game/common/religion/faith_types/00_faith_types.txt
Nok Kundi-5%
Riqan · Holder of the county
nok_kundi · game/common/religion/faith_types/00_faith_types.txt
Yijinai-3%
Tongcheng · Holder of the county
yijinai · game/common/religion/faith_types/00_faith_types.txt

Buildings (16)

Watermills-30%
Province
Levels 1–8: -5% to -30% (8 levels give it)
watermills · game/common/buildings/00_standard_economy_buildings.txt
Royal Armories-20%
Each de jure county of the duchy · culture with Metalworkers
Levels 1–3: -10% to -20% (3 levels give it)
royal-armory · game/common/buildings/00_duchy_capital_buildings.txt
Ruins of the Palace of Ctesiphon-20%
County
palace-of-ctesiphon · game/common/buildings/00_special_buildings.txt
Great Mosque of Djenne-15%
Holder
holy-site-great-mosque-of-djenne · game/common/buildings/00_special_buildings.txt
Maijishan Grottoes-15%
County
maijishan-grottoes · game/common/buildings/cp8_special_buildings.txt
Great Mosque of Samarra-10%
Holder
holy-site-great-mosque-of-samarra · game/common/buildings/00_special_buildings.txt
Hadrian's Wall-10%
Province
hadrians-wall · game/common/buildings/00_special_buildings.txt
Great Wall of Gorgan-10%
Province
great-wall-of-gorgan · game/common/buildings/00_special_buildings.txt
Wetland Farms-10%
County
Levels 2–8: -5% to -10% (7 levels give it)
peat-quarries · game/common/buildings/00_standard_economy_buildings.txt
Water Management-8%
County · culture with Hydraulic Builders
Levels 1–8: -1% to -8% (8 levels give it)
waterworks · game/common/buildings/00_standard_economy_buildings.txt
Forestry-8%
County · culture with Forest Wardens or Forest Folk
Levels 1–8: -1% to -8% (8 levels give it)
logging-camps · game/common/buildings/00_standard_economy_buildings.txt
Wetland Farms-8%
County · culture with Wetlanders
Levels 1–8: -1% to -8% (8 levels give it)
peat-quarries · game/common/buildings/00_standard_economy_buildings.txt
Sacred Pool-8%
County · culture with Hydraulic Builders
Levels 1–8: -1% to -8% (8 levels give it)
sacred-pool · game/common/buildings/temple_citadel_buildings.txt
Qianling Mausoleum-5%
County
qianling-mausoleum · game/common/buildings/00_special_buildings.txt
Quarries-5%
County
Levels 4–8: -5% to -5% (5 levels give it)
quarries · game/common/buildings/00_standard_economy_buildings.txt
Elephantry-2%
County
Levels 3–8: -2% to -2% (6 levels give it)
elephant-pens · game/common/buildings/00_standard_economy_buildings.txt

Laws (1)

Manor Reform-15%
Imperial Policies · Rulers with this law
manor_reform_law · game/common/laws/03_imperial_policies.txt

Dynasty legacies (1)

Power and Prosperity-5%
Law legacy · Members of the dynasty
law_legacy_3 · game/common/dynasty_perks/00_dynasty_perks.txt

What raises Building Construction Cost (1)

Cultural traditions (1)

Industrious+15%
Characters of this culture
tradition_hard_working · game/common/culture/traditions/00_societal_traditions.txt

Source: game/common/buildings/00_duchy_capital_buildings.txt, game/common/buildings/00_special_buildings.txt, game/common/buildings/00_standard_economy_buildings.txt, game/common/buildings/cp8_special_buildings.txt, game/common/buildings/temple_citadel_buildings.txt, game/common/culture/pillars/00_ethos.txt, game/common/culture/traditions/00_societal_traditions.txt, game/common/dynasty_perks/00_dynasty_perks.txt, game/common/laws/03_imperial_policies.txt, game/common/lifestyle_perks/00_stewardship_2_domain_tree_perks.txt, game/common/religion/faith_types/00_faith_types.txt, game/common/religion/tenet_types/00_tenet_types.txt, game/common/traits/00_traits.txt and the English localisation, Crusader Kings III 1.20.0.3. Building chains are shown once, at their strongest level, with the range over their levels. Effects that come only from events or scale with a script value are not listed.