What is the impact of occupant behaviour in life cycle assessment?

Hannelore Scheipers; Eline Himpe; Yanaika Decorte; Stijn Van de Putte; Arnold Janssens

doi:10.5281/zenodo.17435306

What is the impact of occupant behaviour in life cycle assessment?

Hannelore Scheipers; Eline Himpe; Yanaika Decorte; Stijn Van de Putte; Arnold Janssens

Publisher: Zenodo
DOI: 10.5281/zenodo.17435306
Repository: zenodo.org
Language: en

Abstract

The renovation rate of the building stock must increase to reach the 2050 climate goals. One of the methods to reach this goal, is to shift the focus to district renovations. Therefore the Horizon Europe Mission Project Neutralpath has been initiated. This project investigates how PCEDs (Positive and Clean Energy Districts) can be achieved in 5 European cities, in an inclusive manner. PCEDs are districts that produce more energy than they consume, and only use 'clean', i.e. renewable energy. The design of these PCEDs is done through participative and human-centre principles. This research is part of the Neutralpath project and investigates the most optimal renovation scenarios in existing districts in a holistic manner, with the Muide Meulestede district in Ghent as case study. Energy use, the environmental impact over the full life cycle and costs will be considered. As sub-research, the impact of integrating dynamic simulations in LCA is investigated, with a focus on the impact of occupant behaviour. The study finds that both comfort preference levels and insulation strategies (choice of insulation + finishing materials) significantly affect the total environmental impact of renovation scenarios, and thus the most optimal renovation scenario. Further, comparing dynamic simulation results with those of the Belgian LCA tool TOTEM reveals large discrepancies due to simplified energy use calculations used in TOTEM.

Full text

What is the impact of occupant behaviour in life cycle assessment? Integration of multi-zone dynamic energy simulations into LCA for residential building renovation RESEARCH GROUP BUILDING PHYSICS Hannelore Scheipers, Eline Himpe, Yanaika Decorte, Stijn Van de Putte, Arnold Janssens Contact [email protected] https://neutralpath.eu/city/ghent/ Funded by the European Union Part of the Neutralpath project •Horizon Europe Mission Project •Ghent = fellow city •PCED = Positive and Clean Energy District: ▪More energy produced than consumed (annual basis) ▪Clean, i.e. renewable energy •Design PCEDs by participative and human-centre principles 1. Occupant behaviour in Life Cycle Assessment (LCA)? •The environmental impact of buildings is often calculated using a simplified energy calculation to estimate the operational impact. The influence of occupant behaviour, i.e. the setpoints for heating, the heating duration… is often neglected in this approach. •E.g. the simplified Belgian LCA tool TOTEM uses the equivalent heating degree days method (EHDD), with a fixed indoor temperature of 18°C. •Factors such as a sufficiency mindset or energy poverty can lead to a (way) lower energy use than estimated in the simplified calculations. 3. Results •In some cases: only renovating walls + roofs is preferred over deep renovation •Insulating more construction components does not necessarily compensate for a higher comfort preference level •There are large discrepancies between TOTEM and BES model for both the low and high comfort preference level 2. Case study: MuideMeulestede •Environmental impact oLCA following the TOTEM methodology •Occupant behaviour oEROB model developed at the Building Physics Research Group o3 comfort preference levels: ▪Low: living & kitchen 17°C ▪Medium: living & kitchen 19,5°C ▪High: living & kitchen 22°C •Dynamic simulations oModelica language o4-zone building model 4. Conclusion •Important to incorporate occupant behaviour oChoice of materials oComfort preference level •Simplified LCA tools can give inaccurate results for households with energy efficient heating behaviour Muide Meulestede © Bob Van Mol Zaragoza (ES) Dresden (GE) Ghent (BE) Vantaa (FI) Istanbul (TR) Project number: 101096753; January 2023 –December 2027 Scan for full paper (will soon be available) BES Operational EI EHDD Operational EI BES Embodied EI (low impact materials) EHDD Embodied EI (low impact materials) BES Extra Embodied EI (high impact materials) EHDD Extra Embodied EI (high impact materials) nr. Slab on grade Walls Windows Pitched roof Flat roof 1● 2● 3● ● 4● 5● ● 6● ● 7● ● ● 8● ● ● 9● ● ● 10 ● ● ● ● 11 ● ● ● ● ● Single-score environmental impact results of the 11 renovation scenarios categorised per comfort preference level, where the operational energy use was calculated both with BES and EHDD. Climate change environmental impact results of the 11 renovation scenarios categorised per comfort preference level, where the operational energy use was calculated both with BES and EHDD.