Contingencies can be written in various ways. For example, an inspection contingency might give the buyer the unilateral right to withdraw from the contract without penalty. Or, it could specify that the buyers give the sellers the opportunity to remedy defects.

In the latter case, the buyers' deposit could be at risk if they backed out of the contract without giving the sellers the chance to make repairs.

During the fast-paced seller's market of a few years ago, buyers often made offers without contingencies in order to be competitive. In some cases, lawsuits developed after closing when the buyers discovered defects they were previously unaware of.

While it's preferable to include contingencies, there are times when it may be reasonable to waive a contingency as long as you are aware of the consequences before doing so.

For example, recently buyers made an offer in competition on a desirable house in the Oakland Hills of Northern California. They did not include a contingency for the house to appraise for the purchase price.

The appraiser was unable to appraise the house for the agreed-upon price because of a lack of sales in the neighborhood in recent months. Without an appraisal contingency, the buyers could have lost their deposit to the sellers if they backed out because the house appraised a little low.

However, the buyers were aware of the fact that the house might not appraise for the price they agreed to pay. They were willing to increase their down payment to make up the difference. And, the sale went through.

In addition to the price and contingencies, the purchase offer should include such specifics as the deposit amount, the closing date, the date the sellers will deliver possession, any personal property such as a washer or dryer that is included, and any real property such as a light fixture that is excluded from the sale. It is best to be as specific as possible.

The time to tie up any loose ends is before the final contract is signed. Leaving issues to be worked out later can work to your disadvantage. You could find that a previously congenial seller turns cranky if he's asked to pay for defects discovered during your inspections.

For example, let's say that you want to close the transaction and receive possession of your new home on a Friday so that you can move in over the weekend. You are better off specifying a date for closing than you are indicating a closing of a certain number of days from acceptance. If the negotiations take several days, your 30-day closing date could end up falling on a Monday.

THE CLOSING: An uncooperative seller might hold you to this.

Dian Hymer is author of "House Hunting, The Take-Along Workbook for Home Buyers" and "Starting Out, The Complete Home Buyer's Guide," Chronicle Books.