The home inspection business came alive in the 1980s in order for buyers, sellers and agents to competently deal with disclosing property defects. Texas was the first state to license home inspectors. In Michigan, home inspectors are required to have a Builder's license.
There are, however, two major home inspection industry trade associations that require their members to comply with a certain standard of care. They are the American Society of Home Inspectors (ASHI) and the National Association of Home Inspectors (NAHI). States also have trade organizations, like the California Real Estate Home Inspector Association (CREIA).
HOUSE HUNTING TIP: In order to make sure that you get a thorough home inspection, use the best home inspector you can find in your area. Your real estate agent can give you recommendations. It's also a good idea to ask recent buyers in your area who they used for a home inspection. Find out if they were satisfied with the inspection. Or, did they later discover problems that were missed?
It's important that buyers be present for the inspection. A home inspection can take several hours depending on the age and size of the house. If you can't attend the entire inspection, plan to show up at the end of the inspection. This way you can walk through the property with the inspector for a recap of the findings.
Keep in mind that home inspectors aren't hired to comment on aesthetical issues. It's the home inspector's job to point out defects. All homes have defects, even new ones.
What you need to know before you go through with a purchase is (1) the seriousness of the defect; (2) how much it will cost to repair; and (3) how soon it needs to be done. Ask the inspector to prioritize the findings so that you can evaluate the cost consequences.
Your goal is to have a complete inspection report on the property. In order for this to happen, your agent should ask the listing agent to make sure that the sellers provide easy access to attic and crawl spaces. Also, the utilities need to be turned on.
Also, request that the sellers and their agent not attend the inspection. This way you can talk freely with your inspector. If it's inconvenient for sellers to leave, reschedule the appointment.
The home inspection should cover the major systems from roof to foundation and everything in between. However, home inspectors usually aren't licensed wood-destroying pest inspectors. The report will be limited to what is visible. It probably won't cover environmental hazards or irrigation systems, spas, swimming pools, septic systems and other components that should be inspected.
For this reason, it's a good idea to start the inspection process as soon as possible after you have an accepted offer. The home inspector might recommend further inspections of systems that he inspects, like the furnace.