Here is a problem i observed,The problrm is about creating floors.
if a single floor(room) is created for whole house then it appears while rendering but if diffenent floors are created then only the floor which is created at first is seen while rendering [:-/]
I dont hink i explained well so here are some pictures to show what i mean
IN THIS ONE I USED COLOR/DEFAULT TEXTURES/USER MADE TEXTURE
AS YOU CAN SEE NON OF THESE WORK OUT.