Why is it,that Most Building has no 13th floor?

It is because of a superstition about the number 13 and the 13th floor of a building. It is supposed to be bad luck or something and I guess they figure that no one would want to go on the 13th floor, but technically the floor labeled 14 is the 13th floor and every floor after that is one less than it says.

It's all superstitious. The number 13 is bad luck, so they don't have 13th floors in hotels.

I think it has something to do with the number 13 not being a lucky number. But, I think it is just a superstition thing and 13 is just a number and nothing is unlucky bout it at all.

As others have stated it is due to superstitious reasons, but I think what you are really looking for is a reason why 13 is considered unlucky.

There are a number of significant reasons why 13 is considered unlucky, the most likely is that when you sit 13 people at a table there will always be one person left out when divided into groups. There is also the theory that there were 13 people at the last supper, and the 13th man was none other then Judas, Jesus' betrayer. In a standard Tarot deck the 13th card is death. The Knights Templar were slaughtered on a Friday the 13th. 13 is the sixth prime number 6 is an unlucky number and has an association with the devil.

I think that it's a contraddiction to believe in God and to think that number 13 can make you unlucky. Superstition is from satan,when you have fear of something he has the occasion to scare you more and to make you believe that the thing which scares you it's true