if you are coming from Arrasate, you need to head towards Gasteiz. When you drive along Eskoriatza (not through the village; Eskoriatza will be to your right) and get to a roundabout, turn right. You should see a petrol station to your left and a factory (Zubia) to your right. The faculty is within a distance of about 300m. You will see a stone building to your right (that´s the faculty you are looking for). There is a parking site just before this building.
If you are coming from Gasteiz, you will come to this first roundabout. Then follow instructions