The introduction of the computer to the architectural design process have facilitated the possibility to examine a large number of design alternatives by allowing continuous variation between pre defined constraints. However, for the most part, evaluation and comparison of the alternatives is still handled manually in a linear fashion by the designer. This paper introduces a different approach to the architectural design process, which calls for a multithreaded or a non-linear design process. In a non-linear design process design directions and alternatives are generated, presented and evaluated simultaneously, and in real time. As an example for a non-linear design process the Generative Performance Oriented Design model and software tool (GenPOD) are presented and discussed. Moving towards non-linear modes of design arguably increases design creativity by allowing generating and evaluating a greater number and variation of design alternatives.

Double-skin facade (DSF) is regarded as one of the most advanced and promising curtain wall technologies currently available, adopted until recently mainly in cold and temperate climates. Despite their potential for improved thermal performance compared to conventional curtain wall technologies, experience with the application of DSF technology in hot climates is still little. This paper presents the results of the first DSF monitoring in Israel, executed in the first office building in Israel to apply this technology. Results show that the applied DSF technology (mechanically ventilated box window DSF with integrated blinds) has a potential for keeping indoor temperatures up to 2°C below outdoor temperatures (excluding the effect of air conditioning) and reducing solar heat gains without compromising indoor visual comfort. At the same time, they also exposed an inherent deficiency of the system's capacity to prevent air cavity overheating: air cavity temperatures were 10–30°C higher than outdoor temperatures in all facades exposed to direct solar irradiance.

Transitioning from fossil to renewable energies, particularly photovoltaic (PV) energy, could influence building design in terms of environmental evaluation. The aim of this study was to rate a typical office building that complies with the Israeli Standard SI5282, Energy Rating of Buildings, and to evaluate it by life cycle assessment (LCA). An office building in Tel Aviv with four exterior wall construction technologies was modeled as follows: (1) a concrete-block-based wall with minimal windows; (2) a concrete-block-based wall with maximal windows; (3) an autoclaved aerated-block-based wall with minimal windows; and (4) an autoclaved aerated-block-based wall with maximal windows. The electricity sources used to support the building’s operational energy were: (i) 31% coal, 56% natural gas, and 13% PV (adopted in 2020); (ii) 8% coal, 57% natural gas, and 35% PV (planned for 2025); and (iii) 100% PV (planned for the future). A two-stage nested mixed analysis of variance was used to simultaneously evaluate the results of six ReCiPe2016 methodologies. The results show that as fossil fuels are replaced by PV energy production, there is a greater need to use LCA methodology in building design in conjunction with energy standards. The energy rating is recommended to be carried out with an environmental assessment of the production stage of construction. Ignoring the LCA results could lead to the misinterpretation of a building’s sustainability.

Life-cycle assessments (LCAs) were conducted to evaluate sculptured cement mortar tiles, proposed by Hershcovich et al. (2021), and conventional cement mortar flat tiles for thermal insulation of a typical residential building in Mediterranean climate. The production (P) and operational energy (OE) stages were compared between the sculptured tiles and the conventional flat tiles. The P stage used Portland cement with 95% clinker (CEM I) and Portland limestone cement with 65% clinker (CEM II). The OE stage used 31% coal, 56% natural gas, and 13% photovoltaic (PV) (adopted in 2020) and 8% coal, 57% natural gas, and 35% PV (planned for 2025). The ReCiPe2016 single-score method was used to assess environmental damage over short (20 years), long (100 years), and infinite (1000 years) time horizons of living pollutants. The results show that the use of sculptured tiles caused environmental damage in the short time horizon and environmental benefits in the long and infinite time horizons in the 2020 scenario, while it led to environmental benefits only in the infinite time horizon in the 2025 scenario.

The Israeli Standard SI5282 rates buildings according to the operational energy (OE) used to support their heating, cooling, and lighting needs. When it was proposed, OE was generally considered to be derived from fossil fuels, such as coal. However, at present, Israel is in the process of transitioning to cleaner energy sources, such as natural gas and renewables. In light of this change, the question that guided this study was as follows: should the production (P) stage of external shading devices be taken into account alongside the OE stage? In this study, we aimed to evaluate the P (environmental damage) and OE (environmental benefit) of five external shading devices with equivalently high energy rates that were installed in a typical office building using cleaner OE sources. We evaluated the environmental impacts using the ReCiPe2016 method. The results indicated that the P stage of the five shading devices led to significantly different degrees of environmental damage, thus reducing the environmental benefits related to the OE stage. Therefore, the five similarly rated shading devices could no longer be considered as equivalent sustainable alternatives. As such, we recommend that the energy rating be supplemented with a P stage environmental evaluation.