Due south of Uppsala, there are three buildings, the Skokloster church built 1230 by the Cistercian order and the “old stone-house”, built on top of the old brick kiln used for the construction of the church. But the dominant building is Skokloster palace. The stone-house has been rebuilt several times. The present building lay out dates from 1740. During the 20th century the old stone-house was heated to human comfort by electric heaters. The aim of this paper is to describe the different alternatives for replacing the electric heating system with a more energy efficient and sustainable system. The alternative finally chosen is described. It is a heat-pump system with bore holes in rock as heat source and traditional water heating system with radiators as heat-sink. The energy certification for the stone-house gives a consumption of 94 kWh/m2 and standard year to be compared with the government request of max. 110 kWh/m2.