High-resolution combined building stock and building energy modeling to evaluate whole-life carbon emissions and saving potentials at the building and urban scale

Abstract

As global and local actors seek to address climate concerns, municipalities, regions, and countries are developing policies for the built environment to reach carbon neutrality. In most cases, however, current policies target new construction and operational carbon emissions only, thus omitting the significant carbon emission saving potential resulting from the reactivation of embodied carbon in existing buildings. This article describes the development of a high-resolution combined building stock model (BSM) and building energy model (BEM) on both building and urban scale using all residential buildings of Ithaca, NY, USA as a case study. The model offers a holistic, detailed and local perspective on operational and embodied carbon emissions, associated saving potentials at both the building and urban scale, and the linkages, trade-offs and synergies between buildings and energy use as a basis for decision-making.A circular economy (CE) in construction posited on the reuse and recycling of existing building materials, necessitates a detailed material inventory of the current building stock. However, the scale and nature of this endeavor preclude traditional survey methods. The modeling process described in this article instead engages a bottom-up data aggregation and analysis approach that combines detailed construction archetypes (CAs) and publicly available, higher-level municipal geospatial data with building metadata defining occupancy and systems to create an autogenerated, detailed 3D geometry. The resulting BSM and BEM can simulate both embodied carbon content and operational carbon emissions of individual buildings within a municipal study with minimal required input data and a feasible computational effort. This provides modelers with a new spatial and geometric fidelity to simulate holistic renewal efforts, and inform carbon neutrality policies and incentives towards the decarbonization of the built environment.