Our first experience with a wine cellar was when we purchased a free standing wooden one from IWA (International Wine Accessories). We bought it because we were collecting far too many bottles of wine to store at room temperature and expect that they would still be good if we didn't drink them for five years or more. When we decided to move to Hawaii, we had a home built. We included a built in wine cellar and thoroughly loved it. A chiller will keep the temperature and humidity constant, which, in turn, will prolong the life of your wines.
When one has a wine cellar built in, especially in new construction, the cost is reasonable. For a 150 to 175 square foot room, the cost would be around $12,000 to $15,000. That covers applying extra insulation to the walls, floor and ceiling, finishing the inside, usually purchasing prefabricated racking (about $10,000 to $12,000 for a room that size) and installing a chiller. When you are done, the fun begins. Now you can purchase extra of those wines you like most and store them in your cellar. Currently we are drinking merlots, cabernets and red zinfandel that are eight to fifteen years old. Some of these wines are far more enjoyable aged as compared to when they were released.
A word of caution. If you have a wine cellar built, make sure your contractor has experience installing them or insist that they talk with the company furnishing the chiller. Typically, these companies have specifications they can supply to the contractor to facilitate constructing the room correctly. We did not understand the significance of insulating and vapor proofing the room when we had the first cellar built; neither did our contractor, and there ended up being some things I did differently when we moved and had to have another cellar built in.
In short, we found the following to be key principles when installing a wine cellar: