When you are looking for homes to purchase, examine:

Carpentry work - check windows for ease of opening and closing, check floors for squeaky or soft spots.
Floors and walls for any cracks and damp spots.
Insulation and ventilation in attics, crawl spaces, and garages.
Mechanical and plumbing systems for proper working order.
Drainage on property to determine that water flows away from the house.
Crawl space for dryness.
In the written offer, request a "whole house inspection" by a qualified home inspector.
Make request for necessary repairs in writing.