Integrating parametric design, field-evaluated hygrothermal simulation and life-cycle assessment for early-stage low-carbon envelope decisions: a pilot demonstration on a full-scale salt-brick pavilion in a hot-arid climate

Purpose This study pilot-demonstrates the Climate-Adaptive Mineral Envelope (CAME) workflow, integrating fragmented analytical tools within Grasshopper to support low-carbon envelope decisions for hot-arid construction.Design/methodology/approach A discretised Schwarz P envelope underwent structural verification and NSGA-II optimisation using a Gaussian-process surrogate trained on 120 EnergyPlus simulations. A Pareto-knee configuration was built as a 3,000-brick Himalayan salt pavilion exhibited at Dubai Design Week 2024. Nine-day monitoring of operative and surface temperatures and relative humidity informed calibration of an EnergyPlus model using the Effective Moisture Penetration Depth algorithm. Screening life-cycle assessment (LCA) and costing completed the work flow.Findings Surrogate RMSE was 0.38 °C under leave-one-out cross-validation and 0.42 °C across six out-of-sample simulations. Calibrated model RMSE was 1.06–1.31 °C, with CV(RMSE) of 3.4–3.6%. NMBE was not calculated, precluding full ASHRAE Guideline 14 compliance claims. Mean operative temperature in the salt cavity was 3.1 °C below the concrete-masonry-unit reference, with a 6.3-h phase shift and 0.43 decrement factor. These contrasts are descriptive because observations were serially correlated, monitoring covered one pavilion and one panel, and cavity-node convective exposure was unquantified. Screening LCA indicated 69.7% lower embodied carbon, remaining ≥62.3% across a ±50% sensitivity band.Originality/value The workflow connects parametric design, surrogate-assisted optimisation, fabrication, monitoring and calibrated simulation with carbon and cost screening, assigning explicit evidence-status classifications.Practical implications Comparative thermal, carbon and cost screening is delivered within one working session. Permanent salt-envelope application requires binder redesign, deliquescence-resistant detailing and code-compliance evidence.