Development of environmental benchmarks for the Belgian residential building stock

Abstract

Over recent years Belgium has made meaningful effort in adopting Life Cycle Assessment (LCA) in building practice to improve building environmental performance. Today, architects can compare the environmental performance of different building designs with an online calculation tool that incorporates the national LCA method. However, they are still lacking environmental benchmarks to position themselves within current building practice. Furthermore, such benchmarks play an important role in the development of environmental targets in building regulation. In this research, benchmarks are defined for new residential buildings in Belgium. A bottom-up approach is followed consisting of a statistical analysis of reference buildings to define limit, reference and best practice values. The buildings are based on four representative typologies for Belgium, ranging from detached houses to apartments. Different variants are assessed including various energy performance levels and construction types (solid versus timber). The buildings’ life cycle impacts are calculated including the embodied (material) and operational (energy) impacts. Results are reported both for an aggregated environmental single-score and for Global Warming Potential (GWP). The calculated reference values for life cycle and embodied GWP (20 and 7 kgCO2eq/m2.year) are comparable to existing benchmarks in the literature. The results further highlight that building compactness provides the largest impact reduction, followed by construction type. Finally, limitations are discussed and recommendations are formulated for developing future benchmarks.

Preliminary study on the use of Big Data for environmental benchmarks of residential buildings in Flanders

“…Figure 6 compares the obtained results with the results for solid construction from an earlier study on the SuFiQuaD archetypes [16]. Overall, the impacts are slightly higher for the EPB cases than the SuFiQuad cases: the mean values of both sets differ 2.4 mPt/m²GHFA for the embodied impact (51.4 mPt/m²GHFA for EPB and 49 mPt/m²GHFA for SuFiQuad), 1.9 mPt/m²GHFA for the operational impact (42 mPt/m²GHFA for EPB and 40 mPt/m²GHFA for SuFiQuad), and 4.1 mPt/m²GHFA for the total environmental score (93.1 mPt/m²GHFA for EPB and 89 mPt/m²GHFA for SuFiQuad).…”

“…The cases include four common dwelling types (detached, semi-detached, terraced and apartment) from four construction periods (<1945, 1945-1970, 1971-1990, 1991-2001). A recent study on benchmarking assessed the life cycle environmental impact of the four cases from 1991-2001 [16]. A larger set of buildings was defined in the context of the European project TABULA/EPISCOPE [17].…”

“…However, it should be noted that all five cases are solid construction types and hence variations in materialisation are limited. As shown in the SuFiQuaD-based benchmark study, timber construction enables significant reductions in environmental impact [16].…”

Life cycle environmental benchmarks for Flemish dwellings

“…In a preliminary study [50], five sample cases were selected from the representative SFH to test the workflow between the EPB data and the LCA modelling and compare the results to an earlier benchmarking study [51] of Flemish dwellings. In this paper, the full set of representative buildings is used to derive benchmarks for the environmental impact of new residential buildings using the Belgian TOTEM tool.…”