How can you manage the dampness issue in houses in Uruguay?

We all know that houses can get very damp in Uruguay in winter.  The way I manage the dampness in my two-storey house is 3-fold:

1. opening all blinds/shutters everyday to get as much sunlight into every room.
2. running a de-humidifier all day (I can get 5L of water a day from my house!).
3. putting containers of water absorbing crystals into all wardrobes and large cupboards (my favourite brand is Fragance Sec).