You will need to run horizontal as well as vertical conduit. Get a pull string put in the conduit when it is installed and make sure that they use 'sweep' bends rather than hard 90 degree bends, then the cabler just uses the pull string to pull the cable through when they are ready to install.
The other option, if your walls line up, is to go from the ground floor up to the ceiling space and then through the ceiling space back to a point that connects to your cabling termination location - a larger "riser" conduit as Pugs suggested.