If the house is inspected before a purchase offer is made, you will know in advance if heating equipment, rewiring, or any other costly repairs or replacements will be needed. If defects are found, you do not necessarily have to reject the house. A purchase offer can include a contingency clause that identifies what needs to be corrected before the sale is finalized. Another option is to offer a lower purchase price based on the cost of correcting the problems. After an offer to purchase contract is signed a thorough inspection should be done.
Some lenders require a mechanical and structural inspection by a qualified house inspector.
Even if a lending institution does not require such an inspection, you may want one. Reserve the right to cancel or renegotiate a purchase agreement if a professional inspection reveals significant defects. If you decide to hire a professional inspector, be there when the inspection is done. Follow him or her around. It is important to know what is being checked, why, and the condition of each area.