Environmental health in subway stations, a typical type of urban underground space, is becoming increasingly important. Ventilation is the principal measure for optimizing the complex physical environment in a subway station. This paper narratively reviews the environmental and health effects of subway ventilation and discusses the relevant engineering, environmental, and medical aspects in combination. Ventilation exerts a notable dual effect on environmental health in a subway station. On the one hand, ventilation controls temperature, humidity, and indoor air quality to ensure human comfort and health. On the other hand, ventilation also carries the potential risks of spreading air pollutants or fire smoke through the complex wind environment as well as produces continuous noise. Assessment and management of health risks associated with subway ventilation is essential to attain a healthy subway environment. This, however, requires exposure, threshold data, and thereby necessitates more research into long-term effects, and toxicity as well as epidemiological studies. Additionally, more research is needed to further examine the design and maintenance of ventilation systems. An understanding of the pathogenic mechanisms and aerodynamic characteristics of various pollutants can help formulate ventilation strategies to reduce pollutant concentrations. Moreover, current comprehensive underground space development affords a possibility for creating flexible spaces that optimize ventilation efficiency, acoustic comfort, and space perception.

The global issue of climate change has accelerated the international commitment to net-zero carbon emission development. Decarbonizing the building sector has been put on several governments’ sustainable development agendas. To provide a reference for decarbonizing the building sector, this paper summarizes the U.S. experience in zero-carbon buildings (ZCBs) from the aspects of policies, codes, and standards at the federal and local levels and those of professional societies. Based on the definition and boundaries of ZCBs, this paper introduces policies on building energy efficiency, electrification, on-site renewable energy deployment, and “buy clean”, illustrating highlights in building phases, energy systems, materials production, and fiscal incentives. The synergic efforts and coordination between federal and local levels and with professional societies are also introduced. Successful experiences in policy and standard implementation are summarized, including the systemic work of multilevel governance, clearly defined goals and stringent policies, constant upgrades of codes and standards, transparency in reporting and information sharing, and increased financial and investment opportunities. This paper provides concrete recommendations for developing zero-carbon building policies.

The energy crisis in Europe requires cost-effective evaluations of residential heating strategies to reduce costs and mitigate greenhouse gas emissions. This research studied different heating systems in China and Europe. Based on heating energy surveys, simulation models were developed and further expanded for European cities. Monte Carlo analyses were conducted to understand the heating demand and utility costs in Rome, Madrid, and Athens. The sensitivity analysis found that electrifying heating systems with heat pumps can reduce household heating costs and mitigate European cities’ dependence on natural gas. However, the high upfront investment may hinder the cost-effective deployment of high-performance heat pump systems. Building envelope retrofits can also provide plausible energy savings despite relatively long payback periods. Financial incentive analyses were conducted to quantify how fiscal measures can improve technologies’ techno-economic performance. Finally, the paper provided policy recommendations on future building cost-effective retrofits and heating electrification in Europe.

In regions with a hot-summer/cold-winter climate, a balance between energy-saving and better daylighting performance is often required for the design of a glass roof system. This research aims to reduce the total energy demand and to increase the useful daylight illuminance (UDI), by introducing a response-surface-methodology-based bi-objective optimization approach for three glass roof system models (no shading, exterior blinds, interior shades). Surrogate models were generated to quantify the effect of the glazing material and shading parameters. Our findings have revealed that, in hot-summer/cold-winter climate regions like Nanjing, properties of the glazing material could substitute the effect of shading parameters to enhance energy-saving potentials. However, the use of glazing cannot make up for the effect on the daylight performance. Glass roof systems with a low U-value glazing material and small-slat exterior blinds are generally recommended as the balanced solution to lower the energy demand and raise the UDI_200–2000. The substitute relations introduced in the surrogate models and optimal solutions have indicated that there are multiple choices to attain a relatively similar goal to produce an energy-efficient building design for construction.

Lhasa combines abundant solar resources with a high heating demand and low winter solar altitude, making residential morphology simultaneously important to operational energy use and roof–façade photovoltaic (PV) generation. Based on a residential-area inventory covering more than 80 residential areas and 15 typical slab-type blocks, this study developed locally constrained parametric prototypes and generated 2186 valid physics-based samples. Thirteen morphological predictors were retained for surrogate modelling, followed by sunlight-constrained bi-objective optimization at floor area ratio (FAR) = 1.5, 1.8, and 2.2. On the independent test set, the selected energy and PV surrogate models achieved R² values of 0.999 and 0.989, respectively. The Pareto fronts at FAR = 1.5 and 1.8 included near-zero annual net-energy solutions, whereas FAR = 2.2 retained a minimum deficit of 0.682 × 10⁶ kWh. Low-energy solutions generally favoured a lower site coverage, continuous elongated slabs, and a greater mean height, whereas high-generation solutions favoured larger building footprints, a lower height, and controlled shading. As FAR increased, façade PV made a larger contribution, but this was insufficient to offset the decline in the rooftop supply and the rise in total energy demand. Energy-balance-oriented solutions generally concentrated the building orientation within 5–15° and the building depth within 14.0–15.5 m, with the density and height requiring a joint adjustment across FAR scenarios. The results provide an interpretable basis for the early-stage morphology screening and planning control of slab-type residential development in Lhasa.

In large-span curved roofs, geometric variation simultaneously affects supporting-structure material demand, building operational loads, and photovoltaic (PV) generation, but these responses are often assessed separately. Using a large-span natatorium as a case, this study developed a 20-control-point free-form building-integrated photovoltaics (BIPV) model over a 58.8 m × 37.0 m roof. Structural, energy, and PV simulations were converted into annualized structural carbon, annual operational carbon, and annual PV avoided carbon. Separate convolutional neural network (CNN) regression surrogates using ResNet18 were trained using 4000 structural samples, 1000 energy samples, and 4000 PV samples, and were coupled with three repeated non-dominated sorting genetic algorithm II (NSGA-II) searches. On independent test sets, structural R² values were 0.9968 for roof-panel mass, 0.9048 for spherical-node mass, 0.9093 for member mass, and 0.9908 for strain energy; the energy and PV models reached 0.9973 and 0.9894. The searches yielded 1530 unique globally non-dominated candidates and showed late-generation stabilization by generation 200. Surrogate screening predicted that M2 (ID187) reduced annualized structural carbon, annual operational carbon, and the net carbon indicator by 8.44%, 3.63%, and 5.61%, respectively, while increasing annual PV avoided carbon by 2.31% relative to M1. Original-workflow recalculation of 100 Pareto candidates yielded MAPE values of 1.01–4.30%. The remaining local deviations did not materially affect candidate ranking, and ID187 retained its net carbon benefit and equal-weight compromise status within the verified set. These results apply to the sampled morphology ranges, case-specific operating assumptions, conceptual linear-elastic structural model, and the verified candidate subset.