The following items must be inspected while the walls are still open:

• Structural members: things that hold the house up.
• Beams, studs and anything else that helps to support floors: - Studs that are not perfectly vertical are a sign of sloppy workmanship and poor quality.
• Stairway foundations and doorways: - Steps must be perfectly horizontal and doors should be hung perfectly vertical.
• Drain venting: - Every toilet, tub and sink drain should have a vent to the outside.
• Roof installation.