create room with exact size impossible

[UbuntuBirdy]

If you don't know how to use a program: blame the program, not yourself!

I like your sense of humor, Hans! [:))]

But I know the frustration of being too lazy to learn the functions of the free software...
Still, this shouldn't be an excuse for such behavior - it's just arrogant and disrespectful!

[dorin]

Maybe this How to draw precisely -mini tip could help.
PS Don't miss Note 2 [:)]
PS2 If you don't need walls you could delete after create room.