Should I think more down the line of building represents infrastructure/laws/ etc.
Basic Buildings
Military Base - cost 50, force remit +1
Economic Base - cost 50, tax income +1
Cultural Base - cost 50, local tax modifier +0.1
If a province has a base and one of the neibouring provinces which belong to the same clan has the same type of the builings, that province has the following bonus.
Branch Castle (Military Base+Military Base)-local defence +20, levy reinforce speed+50
Trade Route (Economic Base+Economic Base)-local movement spped +0.2, local tax modifier +0.5
Theatre (Cultural Base+Cultural Base)-honor +0.02, Revolt Risk-5)
Advanced Buildings
Military
Sword Smith - Cost 100, Infantry Levy +2
Farm - Cost 100, Cavarly levy +2
Training Hall - Cost 100, Infantry Shock +2
Archery Ground - Cost 100, Infantry Fire +1, Cavarly Fire +1
Track - Cost 100, Cavarly Shock +2
and so on.