. You can control the presence of facing walls in the room with Room Options Adds a square or rectangular room with a floor and wall to the drawing. The appearance of the surfaces is determined by the current Perspectives Settings . You can control the presence of facing walls in the room with Room Options
To add a rectangular room:
1 On the Perspectives toolbar click Rectangular Room 
.
The prompt reads "Wall width[n]"
2 Either type a thickness and press ENTER or click two points the required distance apart, or right click to accept the default (previous) value.
The prompt reads "First Corner"
3 Click the first point for the rectangular room floor.
The prompt reads "Second corner or enter length"
4 Click a point to define the direction and angle of the first edge, or type a distance then press ENTER.
The prompt reads "Third corner or enter length [square](TAB switch inside/outside):"
5 Click the final point for the floor. Alternatively, type a distance then press ENTER; or right click to accept the default value – a square room. The TAB key on this prompt switches the final click between the inside and outside of the wall
The prompt reads "Height[n]:"
6 Either click a point on the top of the wall, or type a height then press ENTER or right click to accept the default (previous) value.