Tips for building an underground bunker begin with finding a good place for it. Underground bunkers need to be placed outside of flood zones and away from the water table. Also, it is necessary to check local building codes and regulations to determine if there are restrictions and permit requirements.
Some other things to consider when designing an underground bunker are light sources, since there will not be sunlight available, and water sources that can include a water tank or a water filtration system. Make sure the bunker is not visible, as well. Cover the top with dirt and sod to achieve this.