In order to improve the energy performance of apartment blocks in a cold region of Iran via passive heating, we propose a design modification to the sunspaces/balconies of these buildings. To find the optimum performance dimensions for this proposal, six sunspace configurations with different ratios of glazed to opaque surfaces are simulated. The impact of the main design criteria such as the orientation, the number of glazed surfaces, the orientation and inclination angle of the surfaces, the glazing material, the common wall material and the optimum form and dimensions of the sunspace is evaluated. The results reveal that an optimum designed sunspace is an efficient system for passive heating in cold periods of the year. There are overheating problems during the warmer seasons, which may be eliminated by appropriate shading and ventilation. Our proposed design reduces the heating load of the space under consideration by up to 46%.

Sustainable construction practices rely on carefully selecting building materials and balancing environmental and economic considerations. This study examines the complex link between local climate, market dynamics, and building material selection. Market data analysis, parametric modeling, and brute‐force optimization are used to provide insights into construction decision‐making. Across 5540 simulations, a thorough assessment of the financial and energy performance of various materials for walls, roofs, windows, and floors is conducted. Incorporating Pareto ranking, parallel simulation, and sensitivity analysis, the comprehensive evaluation reveals the intricate tradeoffs between cost, thermal properties, and energy savings. The findings highlight the potential for optimal external wall solutions to reduce U‐values by up to 30% and achieve source energy savings of up to 25% source energy savings across diverse climates. By emphasizing the importance of local context in material selection, this study highlights how energy consumption patterns and transmission losses influence financial and energy performance, thus advancing sustainable construction practices.