Recessed entry

Make horizon line and first vertical edge:

Make converging lines:

Front edge of doorway:

Converging line for top of doorway, and the other edge for the doorway:

Put in the top of the doorway, plus 2 converging lines for recessed wall:

Draw in the recessed wall and floor:

Converging lines for back of floor and ceiling of the recess:

Draw in the door:

Draw in some more finish lines:

From here add textures, details, whatever you want: