I am seeing the skybox even when am inside the house, where I have to see the roof instead of skybox?

Questions & Answers
1

I am seeing the skybox even when am inside the house, where I have to see the roof instead of skybox?

I have set the sandbox from edit->rendersettings.

Can someone help me here?

2

Either the inside of your house has inverted normals, or your clip plane is set too short :)

Geometry can also be rendered invisibile with broken UV's.

3

Plane's are one sided, by default, their facing side will be facing upward.

All triangles/polygons are single-sided unless specified with a particular shader, this is a fast method to let GPU's know what to render and what not to, this is known as backface culling. The direction which they face is called a 'normal' (that is, the normal direction they should face.. on a sphere, the normals are usually facing outward).

Use a box instead, or rotate your plane 180 degrees on a sideways axis :)