Usually you choose to visit and look inside a home if the outside is attractive to you at first glance. But take a little time when you drive past or visit the house to look at some things you can see without entering the house. Upon your first (and maybe last) visit, you may have found the house you want but there may be many things you and your agent can spot as warning signs right away about a house of interest without a home inspector:
(1) Did you notice the style, condition and maintenance of the exterior and yards of the homes in the neighborhood?
(2) Upon arriving at the house, how is the slope of the yard – level or toward the house?
(3) What is the age and condition of the roof?
(4) Does the exterior/siding look in good shape and painted recently?
(5) Any obvious water damage, mold, mildew or “funny smells” inside the house.
(6) Attic – insulation existent and adequate or large stains on ceiling of roof?
(7) Age and condition of kitchen appliances, water heaters, and HVAC systems.
(8) Look around the house to see if any foundation cracks, rainfall drainage, or landscaping issues such as retaining walls and their condition.
Source: http://realtytimes.com/rtpages/20120306_inspection.htm