Inspecting the physical condition of a house is an important part of the home-buying process and should be included in your purchase contract as a condition of closing the sale. One or more professional inspectors should look for defects or malfunctions in the building's structure, systems, and physical components, such as the roof, plumbing, electrical and heating/cooling systems, floor surfaces and paint, windows and doors, and foundation, and detect pest infestations or dry rot and similar damage. The inspector should also examine the land around the house for issues concerning grading, drainage, retaining walls, and plants affecting the house.
Even if the seller provides you an inspection report, it's best not to rely on this alone -- the seller may have chosen an inspector who's not known for rooting out problems.
Ask for disclosures before you get an inspection. In some states, such as California, sellers are required to disclose considerable information about the condition of the house itself and potential hazards to the property. (See Nolo's article Required Disclosures When Selling Real Estate.) But this is just the beginning -- not all sellers know about problems with the house or honestly disclose them. (Sometimes they've lived with a problem for so long that they literally forget it's there!) Nevertheless, the disclosures are useful to hand to your inspector for follow-up on known issues.
Most buyers get professional inspections only after they're in contract to buy the property. The deal is commonly made contingent on the buyers' approving the results of one or more inspections. The buyer arranges and schedules the inspections.
Before paying for a professional inspection, you can conduct your own informal inspection. Look for issues like sloping floors or bowing walls, signs of water damage, missing roof shingles or gutters coming loose, old or low-quality fixtures and appliances, and other signs of wear, tear, or needed repair. The best time to do this is before you make an offer, so that you can save yourself the trouble should you find serious problems. You'll find a checklist and further instructions in Nolo's Essential Guide to Buying Your First Home, by Ilona Bray, Alayna Schroeder, and Marcia Stewart.
Another, less commonly used possibility is to ask the seller to let you do a "preinspection" before submitting your offer. Why, given the cost of these inspections, would you do this? Because if you're in a situation where you're competing against other buyers (which can happen in any market, if a house is particularly desirable), this can help you set your offer apart. You'd most likely be able to submit an offer without an inspection contingency, thus reassuring the seller that your offer price is firm, not something you're likely to whittle away at after you're in contract, based on whatever a later inspection reveals. (On the other hand, you risk coming in with an offer price that's lower than others', having taken the house's problems -- which only you know about at that point -- into account.) Some sellers will refuse to allow preinspections in any case, particularly because, if you alert them to problems with the house, they're then obligated to divulge these to other potential buyers.
Hire a general contractor or home inspector to inspect all major house systems, from top to bottom, including the roof, plumbing, electrical and heating systems, foundation, and drainage. This will take two or three hours and cost you from $200 to $500, depending on the location, size, age, and type of home. Accompany the inspector during the examination, so that you can learn more about the maintenance and preservation of the house, ask questions, and get a real sense of which problems are serious and which are relatively minor. (The inspector will write everything down on the report, so reading it can be a bit scary if you hadn't already seen that, for instance, "cellulose against the foundation" just meant a pile of old leaves that you could easily remove.)
In addition to the general inspector, it's wise to hire a licensed structural pest control inspector, who will create a special pest report on the property (unless the seller has already commissioned one -- pest inspectors, unlike general inspectors, traditionally accept work on properties they've inspected, so they have every interest in finding problems). The pest inspector will look for infestation by wood-boring insects such as termites and flying beetles, as well as evidence of dry rot and other fungal conditions. (For a rundown of all the critters that might munch on or otherwise damage your home, see Nolo's article Common House Pests.) Some general contractors are also licensed pest control inspectors, but they will normally charge extra for doing double duty. Be sure you get a written report of all inspections.
Depending on the property and your personal sensitivities, you may want to arrange specialized inspections for hazards from floods, earthquakes, and other natural disasters. The same goes for environmental health hazards such as mold, asbestos, and lead. And, if the general inspection revealed problems with the roof, foundation, or other areas that are hard to access or potentially expensive to repair, you may also want to hire a specialized inspector.
If the inspection reports show that the house is in good shape, you can proceed with the purchase, knowing that you're getting what you paid for.
If the inspections bring problems to light -- such as an antiquated plumbing system or major termite damage -- you can negotiate to have the seller pay for necessary repairs or to lower the purchase price or you can back out of the deal, assuming your contract is written to allow you to do so.
To learn how to include an inspection contingency in your real estate purchase contract, see Nolo's article Contingencies to Include in Your House Purchase Contract.
For detailed information on all aspects of house buying, including more information on inspections and negotiations, get Nolo's Essential Guide to Buying Your First Home, by Ilona Bray, Alayna Schroeder, and Marcia Stewart (Nolo).