This essay concerns the interpretation of house plans in three-aisled Longhouses and hall-buildings, in Scandinavia during Iron Age. Full scale house reconstructions need a better basis of interpretations to understand the patterns of roof supporting post holes in excavated house plans. This has led to the thesis, presented here, that the layout of house plans during Iron Age is based on geometrical proportions. In order to prove this, geometric house plans were applied and compared with excavated house plans in 11different case studies, including the fortification of Fyrkat Denmark. It was found that all house plans in the case studies indicate, that the geometrical proportions 1:2, 1:3 and 2:3 of a given circle must have been used for the basic layout of the roof supporting post holes, using a compass and a straightedge.

This paper deals with archaeological prospection of an Iron Age farm site in Toland, Fresta parish, Uppland County in Sweden. The purpose of the paper has been to see whether the geophysical methods applied (GPR & EM-38) could produce useful results that could motivate its use in similar surveys in the future. Geochemistry has been used for the purpose of identifying possible activity areas on the site. The results have shown that it is possible with a GPR survey to identify postholes originating from the Migration Period Longhouse at the site. The combining of several methods have been important for the identification and interpretation of several areas of interest..