Effects of different insulation materials on primary energy and CO2 emission of a multi-storey residential building

• Insulation materials effect on building primary energy and CO2 emission was studied.
• Functionally equivalent buildings with varying energy-efficiency levels were compared.
• The optimum versions of the building had lower primary energy and CO2 emission.
• Careful insulation choice is necessary for primary energy and CO2 emission reduction.

In this study, we analyzed the implications of various insulation materials on the primary energy and CO2 emission for material production of a residential building. We modeled changes to the original design of the building to achieve reference buildings to energy-efficiency levels of the Swedish building code of 2012 or the Swedish Passivhus 2012 criteria. We varied the insulation materials in different parts of the reference buildings from mineral rock wool to glass wool, cellulose fiber, expanded polystyrene or foam glass. We compared the primary energy use and CO2 emission from material production of functionally equivalent reference and optimum versions of the building. The results showed a reduction of about 6–7% in primary energy use and 6–8% in CO2 emission when the insulation material in the reference buildings is changed from rock wool to cellulose fiber in the optimum versions. Also, the total fossil fuel use for only insulation material production was reduced by about 39%. This study suggests that enhancing material production technologies by reducing fossil fuel-use and increasing renewable energy sources, as well as careful material choice with renewable-based raw materials can contribute significantly in reducing primary energy use and GHG emission in the building sector.