I am offering to build ANY Redstone contraption. This includes grinders, farms, doors, elevators, you name it I will build it. I will purchase the materials myself and simply add it to the cost, or you can purchase the materials I request. I also will do custom contraptions, so don't be afraid to ask even if you think that the contraption doesn't exist! PM me for a quote. Prices vary depending on location (town or wild) and if excavation is required.
@xharo_der The compactness depends on if you want a button panel on each floor or if each floor just gets an up and down button.
Each floor should have a button on which floor you want to go to. Floors 1-12 + lobby. You can use a 20x60x255 space. Basically 20x60 and bedrock to sky limit. Measurements are not exact and could be a little more or less.