Value comes from the home itself. The 20 year old home may be just as up to date as the 5 year old home. Both are old enough to show any problems that they may have with the structure itself. At 20 years old the appliances may have already been replaced and the heater, A/C, roof and hot water heater may be new. Only a visit will make it possible to determine the value in either home. As in any home sale the home is restricted in worth by the surrounding like homes in the area. Today the appraiser is allowed to use properties that are on the market and not sold as of yet to determine the worth of the property. You will need to consider all factors to determine the value of either home.

Based on the information you are providing I would think that the one built 5 years ago will sell for more than the one that is 15 years old. The older home is 10 years closer to major components needing to be replaced. Other factors will effect the value such as lot size and placement in the delelopment.