This study investigates approaches towards conservation of the historic buildings and historic environments in the large scale urban transformations of Malmberget and Kiruna in northernmost Sweden, and how these can be understood as mitigation measures for negative impact on historic values and architectural qualities caused by the mining activities. Both towns were founded at the turn of the 19th century, to enable mining the rich iron ore deposits in the region. Currently, subsidence caused by mining is affecting the built environments, because the iron ore reaches beneath the settlements. Both towns are designated heritage sites of national interest for the purpose of conserving the cultural environment, and both have conservation plans adopted by the respective local councils. In Kiruna, there are listed buildings,and many buildings are protected in detailed development plans.

The mining company is obliged to compensate for damage it causes. However, compensations primarily cover economic values, and focus on replacing functions, not heritage values. Mitigation measures for negative impact on historic values and architectural qualities can mainly be considered as constituting relocation of some of the historic buildings, and documentation of the built environments that will be demolished. An alternative strategy to compensation for the loss of historic environments seems to be to redefine the built heritage and its significance. ‘Heritagisation’ processes are taking place, in which some of the historic buildings are reaffirmed as representing significant built heritage, and thus are being relocated, while the major bulk of historic buildings, many that have had formal protection, are instead being dismissed as heritage. Thus, ‘de-heritagisation’ is taking place, as the historic values of these buildings are considered to be non-significant, they lose their protection, and are ultimately being demolished.