In the hot desert climate zones, the energy consumption of fully glazed office buildings is too high due to the heavy cooling loads. This problem forced architects to use the High-Performance Glazing Systems (HPGSs) which reduce the solar heat gain and save energy. Despite the high initial cost, the HPGSs are supposed to be economically feasible in the long term. This study investigates and compares the economic feasibility of three HPGSs for an office building in New Cairo. In terms of life cycle cost (LCC), the Low-E, Electrochromic, and Photovoltaic glazing systems are compared to the Clear Double-Glazing as a conventional system. Furthermore, the three economic indicators; Net Present Value (NPV), Internal Rate of Return (IRR), and Payback Period (PBP) are analysed. In conclusion, the Low-E Glazing System has the lowest LCC because of the low disposal cost. Moreover, the Low-E glazing has the highest NPV, IRR, and the shortest PBP (15 years). Due to the high initial and maintenance costs, the Photovoltaic Glazing System has a higher LCC. The Electrochromic Glazing System is not economically feasible due to the highest LCC, the lowest NPV, the lowest IRR, and the longest PBP which exceeds 30 years.

Setting eco-rehabilitation plans for cultural heritage buildings require robust guidelines and assessment mechanism to account for the reuse scenarios as well as the construction and demolition waste management plans (C&D-WMPs). This is problematic with the existence of numerous environmental assessment methods. Nevertheless, it is noted that the majority of building rehabilitation practices pay more concern towards the physical properties of materials rather than their environmental value. Hence, this study provides insights for using two different assessment methods in this regard; ‘Leadership in Energy and Environmental Design’ (LEED) and ‘Life Cycle Assessment’ (LCA). The study adopts a cross-comparative quantitative methodology using a practical case study analysis- ‘Richordi Berchet’ palace - the oldest historic LEED Gold certified building. It investigates the efficiency of LEED materials’ credits to support sustainable building reuse and set C&D-WMPs. Noting that these credits operate in quite a simplistic and abstract manner based on materials’ physical properties; weight, area or volume, hence, the LCA method is used to account for their environmental profile expressed in embodied carbon and embodied energy. This pinpoints cases where the use of LEED measurement criteria provides acceptable results and others where the use of LCA is necessary to yield reliable results-noting that their marginal percentage difference is estimated to be ±15%. This indicates the mutual benefit of integrating LCA to support LEED materials credits in such a way that achieves relevance and reliability of eco-building rehabilitation plans. This aims at bridging the gap between researchers and practitioners’ best practices. It also provides insights for green building rating systems developers to consider the environmental value of sustainable rehabilitation guidelines and set reliable measurement and evaluation mechanism.

Since buildings and their construction materials exploit natural resources as well as the effect on energy consumption and carbon dioxide emissions, evaluating building materials is needed to have more sustainable buildings. This study proposes a methodology to define the proper selection of green building materials that can be used for building façades; whilst taking its thermal performance and energy efficiency into account. Additionally, the study compared the energy consumption for six conventional materials for two types of buildings (Educational, Residential) in four climate zones using a simulation program (DesignBuilder). It included also the embodied carbon and equivalent CO 2 for different types of used external façades materials. The evaluation and results is an important step to identify the suitable material that could be replaced with green material and determine how it performs in terms of simulation results and matching with the proposed criteria. The results show enhancement of thermal comfort when replacing a conventional material Brickwork with an environmentally friendly one (Autoclaved Aerated Concrete Block). Moreover, it has a positive impact regarding sub-criteria (from the proposed framework). However, the proposed green material couldn't achieve the expected performance regarding energy performance (as it achieved a minor enhancement from 3245.07 to 3239.1 KWh, U-value for both materials is close) or embodied energy (as the increase of kgCO2 from 758 to 1649.3 due to cement which is one of its ingredients).

This paper aims to measure the footprint for construction materials and construction and demolition waste (CDW) environmental impacts for a case study building in Egypt through the complete Life Cycle Assessment (LCA) of the building ‘from cradle to grave’. The LCA measures eight impact categories, including carbon emissions and energy demand. Our analysis demonstrates the relative importance of life cycle stages; construction processes and materials manufacturing that make the largest contributions to the buildings’ environmental impacts. The results show that the material manufacturing stage is the most critical stage because of its high contribution (about 70%) of the total environmental impacts. On the other hand the disposal stage contributes (about -10%). The results can help engineers and construction industry stakeholders in Egypt to use more sustainable construction materials and change their CDW management practice.

This paper aims to measure the footprint for construction materials and construction and demolition waste (CDW) environmental impacts for a case study building in Egypt through the complete Life Cycle Assessment (LCA) of the building ‘from cradle to grave’. The LCA measures eight impact categories, including carbon emissions and energy demand. Our analysis demonstrates the relative importance of life cycle stages; construction processes and materials manufacturing that make the largest contributions to the buildings’ environmental impacts. The results show that the material manufacturing stage is the most critical stage because of its high contribution (about 70%) of the total environmental impacts. On the other hand the disposal stage contributes (about -10%). The results can help engineers and construction industry stakeholders in Egypt to use more sustainable construction materials and change their CDW management practice.

There is a rapid increasing in the deployment of photovoltaic but most of its installations are on building facades and roofs. Therefore, to achieve the needed large-scale integration of photovoltaic into our energy system will require large-scale deployment beyond the building scale, which will become a part of our landscape. This paper seeks to improve the functional performance of outdoor spaces through the potential of power generation by photovoltaic in outdoor spaces, in hot regions, and improving the thermal comfort. Site measurements, survey, interviews, a 3D model of a shading device using DesignBuilder software, and Computational fluid dynamics (CFD) simulations were developed as part of the study. A comparison was made between the obtained measurements and simulation outputs for validation. The methodology is demonstrated for a case-study in Borg El Arab New City, Alexandria, Egypt. The simulation shows that the installation of PV, on the rooftop and the South-West elevation, enhanced the thermal comfort, and generated three and half times the annual consumed power for lighting, laptop charging units, and Wi-Fi hotspot. The results show that the installations of photovoltaic on shading device will promote the function of outdoor spaces, concerning the technological devices, and will suffice the need for energy for different outdoor needs.

The study focuses on comparing between three of the high-performance glazing systems (HPGS) available in the market through a simulation of a case study of an office building which is located in New Cairo City in Egypt as a hot desert climate zone. The paper aims to enable the decision makers to select the most suitable HPGS through an integrated assessment which combines between the energy, environmental and economic performances assessment. A clear double-glazing system is used as a basic scenario for benchmarking and compared to the three HPGS scenarios (Passive, Active and Building Integrated Photovoltaic BIPV). An office building model has been implemented by DesignBuilder software to illustrate how this assessment can be applied on a real architectural project. The results show that considering the three performances (environmental, energy and economic) in the integrated assessment can outweigh a scenario at the expense of another one. Although the BIPV has advantages in the energy performance, it has the highest embodied carbon. The Electro-chromic glass has the worst economic performance, however the building lowest CO 2 production. Low-E is the most suitable glazing system for the office buildings in the hot desert climate as it has achieved the highest accumulative points.

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