Digital twin (DT) technology is gaining recognition for its ability to evaluate the environmental impacts of building materials, especially embodied carbon (EC). Although there have been notable advancements in estimating the embodied carbon of new buildings, a significant challenge remains in quantifying EC for existing structures. This study employs a thorough scoping review to investigate how digital twin technology can be used to measure the embodied carbon of the current building stock. A detailed literature analysis was performed using databases including Scopus, Web of Science, Google Scholar, and Avery to pinpoint key methodologies, tools, challenges, and opportunities in this field. The research underscores the unique advantages of digital twins in guiding sustainable decision-making for retrofitting and adaptive reuse projects by providing dynamic and comprehensive lifecycle assessments. In contrast to earlier studies that mainly concentrate on operational energy or new construction, this research outlines ways to incorporate digital twin technology into embodied carbon assessments, highlighting retrofitting as an effective strategy to reduce environmental impact. The findings aim to fill the potential, challenges, and strategies associated with employing digital twin technology to measure embodied carbon in existing buildings.

Reducing embodied carbon (EC) in buildings during the early design phase is a critical strategy for achieving sustainability. For concrete buildings, the column layout and spacing significantly impact EC, since they relate to required slab depths and rebar quantities. This paper focuses on assessing the impact of regular column grid layout design for irregularly shaped flat plate concrete buildings. A parametric algorithm was developed in Grasshopper to optimize column grids in these buildings, aiming to minimize maximum bending moments in the slab as a fast proxy for structural material required. This method allows users to upload custom floor plans and compare potential grid layouts. It uses finite element analysis of the meshed floor slab to estimate the bending moments. The results indicate that floorplans with more irregular notches have many layout outliers, which are extremely inefficient due to large cantilevers. However, in more regular layouts, it is still possible to achieve significantly higher efficiency by selecting the appropriate grid placement and spacing. These findings highlight the potential of an integrated spatial planning and structural optimization approach to reducing material use and lowering carbon impacts in buildings.

This paper asks what can we learn from homeowner modifications of manufactured homes about addressing resilience, accommodation, energy savings, occupation, and flexibility? This phase of research builds upon previous studies conducted in hot arid and hot humid climates. For this paper the authors identified retrofits which decrease heating requirements in Leadville, Colorado with data on solutions tailored to the particularities of climate conditions. The resulting assessment identifies modifications and retrofits and associated typologies.

Quantified assessment through energy modeling evaluates the effectiveness of the homeowner designed retrofits. The results of assessment reveal that homeowners decreased EUI through a range of skirting solutions, changes to envelope, and simple passive methods in the entry sequence. Energy modeling simulation on case studies showed between a 6% and 13% decrease in EUI.

The paper focuses upon assessment of heating mitigation through skirting and envelope retrofits, and the use of mudrooms to condition the entry sequence and act as passive solar batteries.