My house is only three years old. Over that time, the countertop has progressively pulled away from the wall. There is currently about 1/2 inch between the countertop and the drywall. I noticed today that the upper cabinet is now pulling away from the wall, too. I also found while cleaning today that there is an area where the hard wood floor is separating. Why would this be happening and how do I fix it?
Laura, it's normal for some settlement to occur during the first several years after a home has been constructed. Nail pops in Sheetrock, hairline cracks at the corners of walls and ceilings, and little gaps at the top of baseboards are all evidence that a home is settling and are normally not cause for concern. However, ½ inch is definitely excessive and the fact that it's happening with several of the fixtures and finishes in the same area leads me to believe there could be a problem other than normal new house settlement.
You don't mention if the house is on a slab or basement foundation, but my guess is that it's on a foundation and some of the weight bearing support under that section of the kitchen is beginning to fail for some reason. It might even be that it was insufficient from the very beginning and just took this long to become evident. But while the situation might look bad, it's really not cause for panic as in most cases the problem can be rectified. If you have an unfinished basement, at least in the area under the kitchen, the repair should be fairly easy, but even if the basement is finished, the settlement can usually be corrected.
My first recommendation would be to call the contractor who built your home. Many builders offer at least a 10 year warranty on their homes for structural issues and your problem definitely falls into that classification. If you don't know who the builder was, they should be able to provide that information at your local building inspection office. Hopefully the contractor is still in business, but if they aren't, my suggestion would be to have a structural engineer take a look at the situation. They should be able to identify what's causing the excessive settlement and while they may not be able to do the repair themselves, might know some qualified contractors who can do the fix.
Even if you are able to get in touch with the original contractor, it might be a good idea to ask for a structural engineer to get involved. That way you should have the peace of mind that the issue has been corrected once and for all. If the original contractor is reluctant to do the repair or uncooperative, get in touch with the local building inspection office and ask them to do an inspection. If the original construction was done incorrectly or something was left out, they may be able to persuade the contractor that it's in their best interest to make it right.