In a perfect world, houses wouldn't deteriorate over time. In reality, the wear begins as soon as a house is built. Older houses tend to have more maintenance issues. But, even new homes can develop problems within a few years if they were poorly constructed.
Most homes are inspected for damage caused by wood pests -- such as dry rot, termites, fungus, decay and wood-boring beetles -- before they are sold. Who pays to correct the damage -- buyer or seller -- is often subject to negotiation.