To install fees and more. No one could give an estimate but the basics is simple. Run ethernet up the middle and deploy Access Points on each floor as a start. If the floors have coverage issues increase the number of APs.
It's that simple but folk that don't do this, tend to make it a big deal.
we have a 8 floor multistoreyed in which we have more than 30 flats. we want to have wi fifor the building instead of more than 20 independent internet connections . what is the procedure and cost involved.