Before timber and stone houses were introduced to northern regions, varieties of turf houses were the most commonly used architecture. These houses had a wooden structure encapsulated in a shell constructed of grass turf. The different ethnic groups of the north built their houses in different styles and constructions, but the general principle was the same. The Norse of North Norway and also on the North Atlantic islands had a tendency to build their houses on top of the ruins of previous houses. After a few centuries this arrangement produced a settlement mound of highly organic soil. In the research literature, both the turf architecture and the settlement mounds have been described as adaptations to and a function of marginality and lack of timber. This paper reports an effort to test the idea that turf houses on top of settlement mounds may have been a finely tuned ecological system that made use of the capacity of organic soil to produce heat.