Bottom-up LCA building stock model: Tool for future building-management scenarios

Residential buildings have a substantial impact on global environmental impacts. In this paper we present a model that assesses impacts from materials (embodied impacts) as well as from heating (operational impacts) for all residential buildings in Switzerland. Our model builds on an existing high-resolution spatio-temporal building stock model, which estimates the space heating demand of buildings, based on building property and site data. In this work we additionally include the impacts of materials extraction, production, transportation, and disposal of building components (floors, roofs, walls, ceilings and windows). Our model comes with a site- and building-specific default parametrization for all buildings, but it is developed as a tool that allows architects and planners to adapt building and site data with specific information to increase the accuracy of the environmental assessment of the current buildings and future building-management scenarios. We applied the model to ten Swiss buildings and assessed a selection of building-management scenarios to illustrate the application of the tool. The results show that our model estimates fairly accurate values of thermal and ventilation heat transmittance, operational space heating demand, and operational and embodied climate-change impacts for the considered buildings. The detailed modeling results for the ten case study buildings outperformed the simplified version of the model with generic default values for material building composition (using age-grouped building archetypes), emphasizing the importance of adding detailed material information in building life cycle assessments. Therefore, a focus should be placed on obtaining accurate material inventories of buildings in future research. The here-developed model allows for integration of such detailed material inventories, overwriting the provided default values.