Towards a LCA Database for the Planning and Design of Zero-Emissions Neighborhoods

Extensible carbon emission factor database: empirical study for the Chinese construction industry

A carbon emission factor (CEF) database is required for the basis of carbon emission calculation in construction projects. However, the default values for existing CEF databases cannot cover the complex resources involved in a construction project. Therefore, this paper proposes a three-step method to guide the establishment of an extensible CEF database for the construction industry, including (1) data collection and parser, (2) data extension, and (3) data encoding and storage. The data extension mechanisms provide the supply chain perspective considering temporal issues and the accounting perspective to streamline the process. Aiming to address the lack of a comprehensive CEF database for the construction industry in China, this paper uses this method to establish a carbon emission factor database for the Chinese construction industry (CEFD for CCI). This database is open and free with 646 CEFs, including five parts: energy, human, material, machinery, and greenspace. This paper provides a way for developing and less developed countries to establish an expandable CEF database, which benefits the parser, extension, encoding, and storage of new resources, as well as computer access.

The development of an integrated BIM-based visual demolition waste management planning system for sustainability-oriented decision-making

In light of the suboptimal resource efficiency persisting in current demolition waste management (DWM) practices caused by inattentive and profit-driven decision-making due to the lack of tailored stringent legislation, monetary incentives, and benchmarking frameworks, this study aims to facilitate sustainability-oriented decision-making at the demolition planning stage. A practical Building Information Modelling (BIM)-based visual DWM planning system is designed, wherein the system seamlessly accommodates inventory analysis and Multi-Criteria Decision-Aiding (MCDA) algorithms into various interconnected modules. Moreover, this research proposes bespoke algorithms and colour coding schemes to quantify and visualise the recycling value of building components for augmenting the visual guidance of sustainable building design and selective demolition planning. Furthermore, a pilot case study demonstrates the system's applicability in a real-world demolition project. The findings unveil that improving the recycling rate substantially offsets carbon emissions and demolition waste disposal expenditures. The increment in beneficial impacts outweighs the additional energy consumption and costs for implementing sustainable DWM strategies based on the predefined geographical settings. This BIM-based system reforms the conventional demolition planning and DWM decision-making workflow by tackling technical barriers concerning data richness, interoperability, and result interpretation. It equips the users with intuitive visual design guidance and parallel scenario analysis when crafting sustainability-oriented DWM schemes. In summary, this research contributes to familiarising industry practitioners with sustainable DWM schematic design and circular economy principles. Moreover, it prompts the development of customised BIM libraries as repositories for updating and capitalising on DWM-related information that can be adapted to different regional contexts.

LCIA Parameters and the Role of BIM towards Sustainability: Regional and Temporal Trends

Building materials with a low environmental impact are critical to the sustainability of the built environment. The environmental impact of materials can be determined by a Life Cycle Impact Assessment (LCIA), which constitutes multiple parameters such as the water used in a material’s life cycle. To use the LCIA approach for building material selection, its parameters need to be assigned different weights, which is the primary objective of this study. Building Information Modelling (BIM) can play an influential role when using LCIA during the building design process. With this consideration, we study the attention given to environmental sustainability in buildings and the responsiveness of BIM in this case. A multi-regional survey of 120 experts from academia and industry was conducted. The results show the relative importance of LCIA parameters and the focus of the building sector on environmental sustainability. The current and the future responsiveness of BIM towards environmental sustainability is also indicated. To promote the integration of LCIA in building design and performance assessment, the future role of BIM applications is explored. The results will contribute to research and practice in the sustainable built environment by helping select environment-friendly building materials.