Radon testing is something a lot of new ad experienced homeowners are unaware of. Make sure the test has good results. If not, make sure a reliable company resolves the issue before you take occupancy or maybe even consider purchasing. Lead windows & paint is an issue with older houses. Be sure the windows have been replaced, the walls & ceilings have multiple coats of paint(7 or more).
Be very careful with termites. These little white bugs can do some damage! Have a test done even if your house is solid brick & especially if it's solid wood. They can destroy floor beams with ease. An infestation is not likely to show itself like other bugs. A reliable, professional company is important.
The yard is important for many reasons. Visit the house on a rainy day prior to purchasing. Make sure the drains work well & the yard doesn't have pooling water. Look for wildlife like moles, snakes, and bee nests. Having a good idea of what you will be dealing with in inclement weather is always better than going in blind and incurring unexpected cost. This will also affect the basement. Considering basements can leak and cause thousands of dollars worth of damage, its best to not make plans for a man cave or extra storage room, until its checked out. Look at the walls for cracks and fractures in the concrete, rock, or mortar. Hire a waterproofing company to give insight on the issue on a rainy day.
These issues must be looked at thoroughly. Any seller may seem irritated at the length of time it will take to perform these tests. If they live in the house it could be worse. Many potential homebuyers just see fresh paint and hardwood, and they are sold. Don't experience buyer's remorse on the single most largest purchase in your life. Most people get loans to buy & if you have to shell out thousands for repairs, or get another loan for repairs, you may be stretched thin.
Before you star shopping you should call the companies for credentials and references. Once a list is put together with every company you need , start shopping with a realtor. Do not use people your realtor suggests. Get your own inspector! Call your own contractors! The only recommendation you may want to consider from a realtor is the moving company. You have made the purchase once you get that far. Too much money is contingent on the information provided by these companies, to use someone they may work with and recommend on a regular basis. Home inspections should be detailed & informative. Brand new houses come with builder defects. Old houses come with wear & tear. Which ever you are shopping for, pay attention, or pay way too much. Maybe enough to put you into bankruptcy.