To elevate the house on pillars and to pour a concrete slab as a floor, with a structure in metal that supports it all, instead of just make the foundation directly on the ground will have it´s extra costs.
Today we had an experience that only strengthened our decision! It rained today, it was not the worst rain but it rained quite heavily. And we ended up with water inside our house, since the waters from the mountain/hill behind our house runs down towards all of the houses and in some cases in to the houses also.
We figured that with a raised house we will never have that happen to us, and that will help us to have a peace of mind during heavy rains (especially during the nights).