An inspector will evaluate the structure, construction, and mechanical systems of your would-be home and, if anything is amiss, give you an idea what it will cost to fix. Rather than hiring someone your real estate agent suggests, pick an inspector on your own to guarantee objectivity. Check the credentials, background, and experience of any prospective inspector, and be present at the inspection, which runs three to four hours for the average-size house. (Be wary of anyone who says you needn’t attend or that he’ll be done in an hour.) Then, take the advice seriously. Don’t let an ample patio or your love of high ceilings cloud your judgment when it comes to structural issues. And before you go to contract, make sure the seller will correct any problems and bring the place up to snuff.