The first suggestion by the Malaysian Government was to build houses outside a green zone of 3km from the shore line but was decisively rejected by the local authorities in Aceh
It was anticipated that a smaller tsunami wave than the 10+ metre event that occurred in 2004 would be sufficient for design. The assumption was that this event was rare and it was also stated that in the next 30-40 years that the return period of a tsunami in the area was of the order of 1 in 35 years