Woodpeckers and houses: clever solution?

I recieved this method of detering woodpeckers (in this case a Green Woodpecker in the Buda Hills) from hammering and boring into wooden buildings. Hang balloons, left over from kids' parties etc, over the areas that are being visited by the birds. Apparently this ingenuous, yet simple, method immediately solved the problem for one family, as the woodpeckers stopped visiting and the occupants have slept soundly ever since. However, it remains to be seen for how long those balloons have to be left dangling there!