Most Realtors will tell you that it is necessary to replace your defective siding if you wish to sell your home in a timely manner and for a good price. You will find that trying to sell your home with defective siding can be major deterrent. If you do get an offer the buyer will almost always want a hefty discount because of your siding. Even if your siding is in good shape, you will usually need to replace it because of the negative stigmatism in the market place.