Energy retrofit of the Krsan Castle: From sustainable to responsible design—A case study

• The energy retrofit of a cultural heritage building complex is studied.
• Building energy demands are calculated by means of a dynamic simulation model.
• The effects of energy efficiency measures on buildings energy demand are analysed.
• Energy reductions of more than 80% can be achieved by combined measures.
• The economic analysis showed positive savings to investment and payback periods.

This paper studies the effects of energy efficiency measures on energy demand in the Krsan Castle, which is a cultural heritage complex in Istria (Croatia). The heating and cooling energy demand is calculated by means of a dynamic building energy model based on hourly weather data. The largest individual reductions are obtained with thermal insulation for the heating demand, and with external window shading and natural night ventilation for the cooling demand. Energy reductions of up to 80%, relatively to the existing state, can be achieved by energy retrofit projects which include thermal insulation, energy efficient windows, improved airtightness, mechanical ventilation with heat recovery and passive cooling techniques. The economic analysis revealed that payback periods between 10 and 16 years can be achieved by this kind of energy retrofit projects.