JAUE2024-032: Study on LCA Estimation of Insulation Retrofits in Apartments

Abstract

CO₂ emissions must also be reduced in the building sector to become carbon neutral. Focusing on large-scale retrofitting of apartments, an LCCO₂ assessment and LCC evaluation of a method that allows insulation to be added at the same time during external wall retrofitting (hereinafter “Insulated Dry Method”) was carried out.

The CO₂ emissions of retrofit work by the "Insulated Dry Method" were 4.8-5.0 times higher than those of the conventional tile retrofit work, and by the "Insulated Dry Method" with window retrofits were 6.1-6.3 times higher than those of the conventional one. However, CO₂ emissions during operational times were reduced by 2.6-5.2% with the “Insulated Dry Method” and by 17.0-19.8% when window retrofits were added to this compared with conventional tile retrofits. The LCCO₂ with the "Insulated Dry Method" decreased by 2.4-4.7% compared to conventional tile retrofits, and by 17-19.8% when window retrofits were added. The effectiveness of “Insulated Dry Method” is expected to increase in the future as energy savings during operational times are further developed.

LCC calculations showed that the cost was 1.05 times higher when changing to the “Insulated Dry Method” compared to conventional tile retrofit. This was 1.17 times higher when window retrofits were carried out, but the subsidy scheme would be equivalent to a conventional tile retrofit.