Integrated LCA and Energy Simulation for Envelope Decisions: Climate-Dependent Results

This paper presents a whole-building life cycle assessment of Francis Hall, an academic building at Texas A&M University, to compare embodied and operational impacts under different climates and envelope design choices. The study combines Tally, linked to a Revit model, with EnergyPlus simulations generated through Revit Systems Analysis. A baseline case in College Station, Texas (climate zone 2A) is evaluated and then re-simulated in Chicago, Illinois (zone 5A) to study climate sensitivity. Design variations include three window-to-wall ratios (10%, 30%, 60%), two wall insulation levels, and two glazing types (single and double low-e). Tally reports 13 TRACI indicators; global warming potential, primary energy, and water use are compared alongside annual heating, cooling, lighting, and equipment loads. Results show that operational impacts change more than embodied impacts across scenarios, with cooling dominating in 2A and heating dominating in 5A. Larger window areas consistently increase both embodied and operational impacts, while improved glazing reduces energy use in both climates with only small material changes. Added insulation yields strong benefits in 5A but limited gains in 2A, indicating that its effectiveness is climate-dependent. Sensitivity analysis indicates that moderate variation in internal load assumptions does not alter the comparative ranking of scenarios. The findings demonstrate that climate-responsive envelope design is essential for balancing embodied and operational impacts and that integrated LCA and energy modeling enable more robust early-stage decision-making.