We have already saw the construction site , that's shit , and that cost 38000 gold ... That's useless. But a thing would be fun : set the price of constrction sites to 10000 and to 1500 for the construction material , then , add burning arrows and make an ability to burning weapons for destroy them . ( and make torch a throwing weapon with 0 requirement )
There would be more weapon racks , sieges towers , healing tents ... and more fun in cRPG
EDIT : ALLOW LADDERS !!!