Effect · every source

How to reduce Building Construction Time in CK3

2 sources raise Building Construction Time and 29 lower it in the game files of patch 1.20.0.3 — for this one, lower is better.

build_speed

The biggest reductions

-30%Professional RecruitmentLifestyle perk · Not Adventurer government
-30%Duomo of FlorenceBuilding · Province
-20%Ora et LaboraTenet · Counties of this faith

What lowers Building Construction Time (29)

Traits (1)

Architect-15%
architect · game/common/traits/00_traits.txt

Lifestyle perks (1)

Professional Recruitment-30%
Not Adventurer government
professional_workforce_perk · game/common/lifestyle_perks/00_stewardship_2_domain_tree_perks.txt

Cultural traditions (1)

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

Culture pillars (1)

Communal-10%
Provinces of this culture
ethos_communal · game/common/culture/pillars/00_ethos.txt

Innovations (2)

Cranes-15%
Characters of this culture
innovation_cranes · game/common/culture/innovations/00_late_medieval_innovations.txt
Manorialism-10%
Characters of this culture
innovation_manorialism · game/common/culture/innovations/00_early_medieval_innovations.txt

Tenets (1)

Ora et Labora-20%
Counties of this faith
tenet_ora_et_labora · game/common/religion/tenet_types/00_pam_tenets.txt

Holy sites (2)

Chakla-15%
Chakla · Followers, while the faith holds it
chakla · game/common/religion/faith_types/00_faith_types.txt
Chakla-5%
Chakla · Holder of the county
chakla · game/common/religion/faith_types/00_faith_types.txt

Buildings (19)

Duomo of Florence-30%
Province
Levels 2–4: -10% to -30% (3 levels give it)
duomo-florence · game/common/buildings/ccp3_special_buildings.txt
Forestry-20%
Province
Levels 1–8: -3% to -20% (8 levels give it)
logging-camps · game/common/buildings/00_standard_economy_buildings.txt
Elephantry-20%
Province
Levels 1–8: -3% to -20% (8 levels give it)
elephant-pens · game/common/buildings/00_standard_economy_buildings.txt
Quarries-20%
Province
Levels 1–8: -3% to -20% (8 levels give it)
quarries · game/common/buildings/00_standard_economy_buildings.txt
Forestry-16%
County · culture with Forest Wardens or Forest Folk
Levels 1–8: -2% to -16% (8 levels give it)
logging-camps · game/common/buildings/00_standard_economy_buildings.txt
Wetland Farms-16%
County · culture with Wetlanders
Levels 1–8: -2% to -16% (8 levels give it)
peat-quarries · game/common/buildings/00_standard_economy_buildings.txt
Castle-10%
Province · culture with Polders, coastal
Levels 1–4: -10% to -10% (4 levels give it)
castle · game/common/buildings/00_castle_buildings.txt
City-10%
Province · culture with Polders, coastal
Levels 1–4: -10% to -10% (4 levels give it)
city · game/common/buildings/00_city_buildings.txt
Great Mosque of Samarra-10%
Holder
holy-site-great-mosque-of-samarra · game/common/buildings/00_special_buildings.txt
The Colosseum-10%
Province
the-colosseum · game/common/buildings/00_special_buildings.txt
Ruins of the Palace of Ctesiphon-10%
County
palace-of-ctesiphon · game/common/buildings/00_special_buildings.txt
Borobudur-10%
County
borobudur · game/common/buildings/00_special_buildings.txt
Dazaifu Office-10%
Holder
dazaifu · game/common/buildings/00_special_buildings.txt
Temple-10%
Province · culture with Polders, coastal
Levels 1–4: -10% to -10% (4 levels give it)
temple · game/common/buildings/00_temple_buildings.txt
Great Mosque of Damascus-10%
Holder
damascus-mosque · game/common/buildings/ccp3_special_buildings.txt
St George of Lalibela-10%
Province
beta-giyorgis · game/common/buildings/ccp3_special_buildings.txt
Temple Citadel-10%
Province · culture with Polders, coastal
Levels 1–4: -10% to -10% (4 levels give it)
temple-citadel · game/common/buildings/temple_citadel_buildings.txt
Qanats-8%
Province
Levels 3–8: -3% to -8% (6 levels give it)
qanats · game/common/buildings/00_standard_economy_buildings.txt
Wetland Farms-8%
Province
Levels 1–8: -1% to -8% (8 levels give it)
peat-quarries · 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

What raises Building Construction Time (2)

Cultural traditions (1)

Collective Lands+20%
Counties of this culture
tradition_collective_lands · game/common/culture/traditions/00_realm_traditions.txt

Tenets (1)

Megalithic Constructions+25%
Characters holding it as a personal tenet
tenet_megaliths · game/common/religion/tenet_types/00_tenet_types.txt

Source: game/common/buildings/00_castle_buildings.txt, game/common/buildings/00_city_buildings.txt, game/common/buildings/00_special_buildings.txt, game/common/buildings/00_standard_economy_buildings.txt, game/common/buildings/00_temple_buildings.txt, game/common/buildings/ccp3_special_buildings.txt, game/common/buildings/temple_citadel_buildings.txt, game/common/culture/innovations/00_early_medieval_innovations.txt, game/common/culture/innovations/00_late_medieval_innovations.txt, game/common/culture/pillars/00_ethos.txt, game/common/culture/traditions/00_realm_traditions.txt, game/common/culture/traditions/00_societal_traditions.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_pam_tenets.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.