Sustainable Urban Development Approach in Residential Building Sustainable Urban Development Approach in Residential Building

Globally, due to its damaging effects on energy, consumption, health, well-being, and air pollution, the urban warming phenomenon is gaining worldwide awareness from scientists to planners and legislators. To achieve the equation and reach energy-saving urbanization, we must reconcile with the environment by providing a sustainable urban design that works to rationalize energy, reduce the depletion of resources, and reach a sustainable urban environment by providing thermal comfort requirements. To attain three key characteristics that are related to one another d thermal comfort, reduced energy consumption, and reduced CO2 emissions d the study will examine a variety of alternatives (residential group D, G, A, N, and H). They will be examined for the residential groups as the research case study in New Cairo, Egypt through adopting a methodical investigation with the aid of the Envi-Met and Energy Plus (Design Builder) simulation tool. Finally, the research results achieved through providing residential complexes include urban spaces in clusters that work together to reduce total energy consumption while simultaneously meeting external thermal comfort needs in the urban environment, both in terms of the orientation and composition of the residential cluster.


Introduction
T he contemporary world faces many chal- lenges, including the housing increase that accompanies rapid urban development, and this is reflected, as an example in the Arab countries, to a large consumption of energy sources.With the steady increase in housing and the need for housing excessively, Egypt, like many other emerging nations, has a hot, dry environment and, as a result of its population size and economic expansion, is confronting many natural resource-related concerns (Asfour, 2010;Bansal et al., 1994;Fahmy and Sharples, 2008).The idea of sustainable development, which considers three key dimensionsdthe environmental dimension, the economic dimension, and their interactiondappears in urban development studies, and minimize the waste of normal and unnatural energies necessary to achieve that comfort, particularly during crucial times like the summer in some regions and the winter in others (Janssen et al., 2013).As such, the importance of the research falls within the framework of the design of closed residential complexes as an attempt to improve the climatic performance of the external urban spaces of the residential group by achieving thermal comfort through the formation factor (the geometric shape) (Mirzaei and Haghighat, 2010;Gussona and Duarte, 2016) and the orientation of the urban components of the residential groups (Simon et al., 2020).
In Egypt, Middleton and others point out that the country is situated in hot, arid climates.As a result, a lot of planning projects have been done to manage population growth (Barakat et al., 2017).Unfortunately, the rapid growth of the population meant that there was not enough time to do full environmental studies for the built and natural environments, where buildings and open areas need to be able to adjust to the changing climate (Middleton and Thomas, 1997).Urban design is heavily reliant on climate interactions that can make or break people's thermal comfort.This brings us to the need for a comprehensive understanding of all the factors that affect people's thermal comfort in the city.Taking it one step further, we use this knowledge to help urban designers and planners make better decisions.That way, their designs will help reduce energy use and make people more comfortable (El Araby, 2002).

Urban formation
The proportion and dimensions of the different buildings have a direct effect on the amount of solar radiation that it receives (Barakat et al., 2017;Middleton and Thomas, 1997;El Araby, 2002).It was found that the optimal ratio of the elongation of the building in hot areas is1: 1.3.It was found that the process of monitoring and analyzing the urban components depends on the building mass and the external space in terms of Refs (Liu et al., 2019;Hegazy et al., 2017): (1) The geometric shape of the building block (van Dijken et al., 2012;Collado and Bustos Romero, 2021).( 2) Geometry and type of external space.
The thermal comfort of an area depends heavily on its urban morphology.To better understand the relationship between thermal conditions and urban sprawl, this observation underlines the importance of controlling the impact of building area ratio when measuring the effects of urban sprawl on local thermal performance (Zhang et al., 2022).
Egypt has made significant contributions to the field of urban geometry and its effects on microclimates.Several studies focused on the urban forms of new urban communities, while others focused on informal settlements or historic settings (Fahmy et al., 2020).
According to Johansson (Fahmy et al., 2017), neglecting the thermal performance of outdoor spaces in urban design processes is one of the most significant reasons for urban design degradation.As a result, urban planners and decision-makers should take into account findings from urban climatology studies in their future urban plans.In particular, outdoor spaces within residential compounds, which are essential to sustainable cities, should be evaluated for outdoor thermal comfort in public areas.This can potentially improve the quality of life in a city by ensuring that residents are adequately served by outdoor spaces (Mahmoud, 2019).
There is a strong relationship between the design and layout of buildings in urban areas and the potential for an increase in the amount of energy needed to cool buildings in hot climates, such as Egypt, to guarantee the comfort of occupants.The increased energy demand associated with air conditioning systems has a detrimental effect on the constructed environment by raising the Urban Heat Island Index (UHI) (Chen and Ng, 2012;Krüger et al., 2011).

Research objective
The research's main aim is to create efficient residential buildings from thermal comfort (PPD, PMV, and operative air temperature), Co2 emissions, and energy efficiency (envelope heat gains) point of view, in a hot arid climate, using New Cairo city in Egypt, as the research case study.This will be achieved at two levels.The first one is the urban level, where buildings will be evaluated regarding their forms using ENVI-MET in their urban layout and orientation with respect to shallow planteair relations within urban environments to get the ideal predicted mean vote (PMV).The second level takes the five residential building group studies, a base case and a proposed case, which were evaluated using the Design Builder software through dynamic simulation.The proposed case is based on the best and worst orientation strategy.With the aid of computer tools, the study used an inductive analytical approach to come to its conclusions.Moreover, a portion of the qualitative methodology was applied when comparing the outcomes as shown in Fig. 1.

Research hypothesis
The main hypothesis is that positive results can be achieved by applying urban sustainability concepts to closed residential communities in the urban design phase by studying the effect of the urban component (building mass and external space) of residential groups in terms of formation variables (geometric shape) and orientation with the help of programs.Urban climate simulation is used to reach the highest levels of compatibility to provide thermal comfort and save the total energy used.

Problem statement
Egypt has taken steps to reduce the population density in cities and address the country's housing issues through new urban growth in most governorates of the country.In recent years, the country has started to experience the phenomenon of 'closed residential communities' (residential compounds), mostly targeting the upper middle and luxury classes.It has contributed to the fast growth of urban space, but it has been limited to the creation of external urban spaces, and a continuous network of streets, without any studies and measurements to determine their thermal performance, and their role in the thermal comfort of the population.Hence, the issue is a lack of understanding and assessment of the climatic function of the urban residential space.It affects the residential community around space in general, and the climate in the city as a whole through what is known as an urban heat island.
Urban areas exist without any research or measurements to determine their thermal performance and their function in the area of population thermal comfort.Therefore, the issue is represented by the lack of knowledge and evaluation of the climatic role of the residential urban space, which has an impact on the neighborhood immediately around the space as well as the overall climate of the city through what is known as the urban heat island.

Methodology
Evaluation of the built environment is done either through field measurements or through the use of simulations.In this sense, the ENVI-MET program has been used, which has proven its suitability for this purpose in many studies, theses, and scientific research.It is a three-dimensional mathematical program for simulating the urban and climatic environment (Zhang et al., 2022;Fahmy et al., 2020).A numerical method was used to adapt the microclimatic data and evaluate the energy efficiency of buildings in the urban area (Fahmy et al., 2017;Mahmoud, 2019).
The selected residential clusters are commonly used in New Cairo To evaluate the performance of buildings operating in passive and active modes for both the base case and the proposed case, Design Builder software and Envi-met software were used (Collado and Bustos Romero, 2021).It is available within a set of programs attached to it to enter digital data and drawings of the general location of the urban structure.The ENVI-Met program modeling was used in five different shape alterations applied on a combination of a residential compacted area with multistory, mixed-use building project in new Cairo, Egypt in order to find a better urban solution by focusing on improving the urban microclimate in that city's hot, arid climate as The simulation was conducted for each urban space in the residential group separately for a period of 24 h.
(1) Choosing the 23rd of July as a representative of the most frequent regular day in the summer period.
(2) Orienting the residential group in eight directions.
Each urban space in the residential group contains two points for recording data, a point in the middle of the space and denoted in the name of the group and the number 1, and the second point next to the mass surrounding the space and also denoted in the name of the group and the number 2, to take the  average of the values and obtain the thermal comfort value external urban void.
To help compare and arrange the spaces according to preference in achieving the external thermal comfort requirements, we group them as follows: By taking the average PMV at two points of registration in the outer urban space of the residential group (G), we can thus reach an urban void in the group that achieves the best value of PMV through guidance.For best guidance and worst guidance for inclusion in a Design Builder Program, see Tables 2 and 3.
Simulation results in the urban space of group (G) at the recording point in the middle of the space (G1) as shown in Fig. 2.
Simulation results showed in the urban space of group (G) at the recording point in the middle of the space (G1): (1) The relative stability in the night hours in the thermal comfort rate PMV.(2) We note that the highest value was recorded at 4.219 at 4:00 pm when targeting the vacuum (G1-90), and the lowest value at the same time was 3.73 when targeting the vacuum (G1-0), Fig. 3.

Residential group (D)
The results of the simulation in the urban space of group D at the recording point in the middle of space D1, See Fig. 4.
The results of the simulation in the urban space of group D at the recording point in the middle of space D1 are shown as follows: see Table 4.
(1) The relative stability in the night hours in the PMV thermal comfort rate.(2) We note that the highest value was recorded at 5.39 at 4:00 pm when targeting the vacuum (D1-180)), and the lowest value at the same time was 4.60 when targeting the vacuum (D1-270), Fig. 5.
The results of the simulation in the urban space of group (A) at the recording point in the middle of space (A1) are shown as follows, Fig. 6: (1) Relative stability in the night hours in the PMV thermal comfort rate.
(2) We note that the highest value was recorded (6.35) and it was at 3:00 pm in the direction of space A1-270, but we will standardize the time during the analysis to be at 4:00 pm to converge the value and note the frequency of the timing in most of the urban spaces in residential groups, Therefore, the highest value is 6.268 when directing A1-315 and the lowest value at the same time is 3.12 when directing the void A1-0 and A1-180, Fig. 7.

Residential group (N)
The results of the simulation in the urban space of group (N) at the recording point in the middle of space N) as illustrated in Table 6.
The results of the simulation in the urban void of group (N) at the midpoint of the void (N1) were shown as follows, see Fig. 8.
(1) The relative stability in the night hours in the PMV thermal comfort rate.
Table 2. Average predicted mean vote at two points of registration in the outer urban space of the residential group (G).(2) We note that the highest value was recorded at 6.07 at 4:00 pm when targeting the blank (N1-135), and the lowest value at the same time was 2.91 when targeting the blank (N1-180), Fig. 9.

Residential group (H)
The results of the simulation showed in the urban space of group H at the recording point in the middle of space H1, see Table 7.The results of the simulation in the urban space of group H at the recording point in the middle of space H1 are shown in Fig. 10: (1) The relative stability in night hours in the PMV thermal comfort rate.
(2) We note that the highest value was recorded at 5.72 at 4:00 pm when targeting the vacuum (H1-315)), and the lowest value at the same time was  as shown in Table 8, the best urban void that achieves the best PMV value was monitored from all the residential groups chosen for the study through the simulation output ENVI-MET 4.4.3.

Step two: Design Builder analysis
The second step in achieving thermal comfort, energy efficiency, and a reduction in CO2 emissions is the building form in its layout, which also reduces the buildings' energy consumption.Design Builder software and a weather data file were used to simulate different building forms.As a result, this section examines how the various building shapes in the layout affect thermal comfort, fuel totals, internal gain, and CO2 emissions (Design Builder, 2021).Basic building shapes tested in Envi-met simulation toll were investigated such as G, D, A, H, and N with the best and worst orientations.The effect of the building form was analyzed, and Table

Residential group (G, D, A, N and H)
Design builder simulated the residential group (G, D, A, N and H) which takes the worst and best orientations from the Envi-met program.Throughout urban variables such as the geometric shape and orientation of the building block and the external space in the residential groups and fixing the rest of the other influential urban factors, to determine the extent of the impact of these design  variables on the thermal comfort in the external urban space, See Table 9e13.
12. Result and discussion

Thermal comfort
A metric scale called the predicted mean value (PMV) is used to quantify the level of thermal comfort attained in a given internal area.To attain the comfort zone, this metric's value should range from 1 to À1, according to the Egyptian code for energy.It was discovered throughout the simulation that the design-results builders for the air temperature co, relative humidity%, and operational temperature co were off, which is similar to the output of the Envi-met program.Table 2 illustrates the residential groups with the best orientation with the best range of PMV value, which shows that the residential group achieves a comfortable value of PMV inside the zone as shown in Table 14.

Internal gain
Internal gains include equipment, lighting, occupancy, solar, and HVAC heating/cooling delivery.The tests conducted illustrated that the adaptation of different residential shapes which analyzed any air supplied into the zone through the HVAC system will have a sensible cooling impact on that zone, which is known as the zone.It includes any 'free cooling' due to the introduction of a relatively cool outside air.Cooling always shows a negative heat gain in the results.It is best thought of as part of the zone heat balance that the residential group (N) consumed the least energy (93197 kwh) with an obvious difference, Residential Group (H) consumed 95288 kwh However, Residential Group (D) consumed 103722 kwh, Residential Group (A) 108556 kwh, Residential Group (G) achieves 136841 kwh compared with Residential Group (D) with 136841 kwh, while we found that in residential  group H and N, there is a little reduction between the best and worst orientation.Otherwise these are the shapes that consume less energy from all the residential groups as illustrated in Fig. 12.Moreover, there is a huge difference between the best and worst orientation of residential groups N and H in July, see Fig. 13 and 14, which is from the hottest month in the year as shown in Tables 15 and 16 (see Fig. 14).

Fuel total
Fuel consumption is broken down by electricity which is the total building electricity consumption.The graph shows that the consumption rate of residential groups follow in the modification of the simulation with the peak range of 214466 (kWh) in the residential group (G) compared with Residential Group (H) with 159858 (kWh), as shown in Figs.15e17.

Co2 emissions
A carbon dioxide analysis has been conducted for the six strategies of research, based on the building's fuel consumption for the mixed mode ventilation (natural and mechanical) and for the working of other activities such as lights and computer equipment (see Fig. 16).It was found that Residential Group (H) achieves the lowest emitting value of 667.5 Kg.Moreover, the residential group (G) reached 1058.2Kg, while Residential Group (N), Residential Group (A), Residential Group (D), respectively, See Table 17.

Conclusion
This study is one of the research contributions that deals with the relationship between the general urban climate and the microclimate in the residential urban space in Egypt.The research discusses the study of urban sustainability and its cycle as a tool for energy conservation by reducing the urban heat island phenomenon using the strategy of passive technologies through the design of fat blocks whose components interact (the mass constructivism and external space) with the determinants of the general urban climate.
External thermal comfort results from the exchange of heat and humidity with the human body, and the role that the average radiant temperature plays in feeling heat.The airspeed also contributes to this, in addition to the metabolic heat produced by the human body according to the activities it performs, as the external temperature comfort of a person is a value that is valued.Calculate it through climatic and physical measurement parameters.It was noted in the results that there are urban spaces in the same residential group that achieve better PMV values than those in other residential groups, and this helps in making the design decision when constructing closed residential complexes, but in this research, we arranged the preference by taking the best value from each residential group and coming out to achieve.The research aims to achieve thermal comfort requirements while reducing the amount of energy consumed in the urban space in terms of orientation and group formation so that it is a proposed model that contributes to providing residential complexes that contain urban spaces in groups that work to achieve the external and internal thermal comfort requirements.
The ENVI-MET and Design Builder Simulation program has proven its suitability for this purpose in many studies, theses, and scientific research.It is a three-dimensional mathematical program for simulating the urban and climatic environment that is available within a set of programs attached to it for entering digital data and general site drawings of the urban structure.
Simulation using the ENVI-MET 4.4.3 program for the external spaces of the commonly designed residential groups in the New Cairo area by choosing: (1) Residential Group (G).
We note in the previous results that there are urban voids in the same residential group that achieve better PMV values than in other residential groups, and this helps in making the design decision when constructing closed residential complexes, but in this research, we will arrange preference by taking the best value from each residential group and come out to achieve the research goal of achieving thermal comfort in the external urban space and using less energy through simulation programs in terms of engineering form and guidance for the urban component of the residential groups to be a proposed model that contributes to providing urban spaces that work to achieve the requirements of external thermal comfort.
To create a sustainable society, it is important to make sure buildings are as eco-friendly as possible.It is important to have the right tools at the start of the design process to help designers come up with better, more efficient designs.In conclusion, the optimization data from the building design multidimensional optimization model used in the case study demonstrate a substantial improvement in energy performance and a marginal improvement in the outdoor and indoor thermal comfort.

Fig. 6 .
Fig. 6.Thermal comfort in the urban space of group (D) at a registration point in the middle of space D1 at 4:00 pm.

Fig. 8 .
Fig. 8. Thermal comfort in the urban space of group (A) at a registration point in the middle of space A1 at 4:00 pm.

Fig. 10 .
Fig. 10.Thermal comfort in the urban space of group (N) at a registration point in the middle of space (N1) at 4:00 pm.

Fig. 12 .
Fig. 12. Thermal comfort in the urban space of group (H) at a registration point in the middle of space H1 at 4:00 pm.

Fig. 13 .
Fig. 13.Summarized the first steps of the measurements of the residential groups.

FigFig. 17 .
Fig. 16.Electricity for the best and worst orientations of residential group N in July.

Thermal Comfort Parameters Building Shapes Environmental Factor Air Temperature Radiation Temperature Relative Humidity % User dissatisfaction index PPD Thermal comfort index PMV Metabolic rate Air Velocity Clothing Insulation Rectangle Ellipse U-Shape Triangle CO2 Emissions Orientation Thermal Comfort Range Energy Consumption Modelling Simulation Boundaries Personal Factors Other Factors Age Clothing Rate Activities Level Skin Temperature Adaptive Behavior Time Site Climate Fig
. 1. Standards and variables of thermal comfort measurement.illustrated in Table 1 (Nacional de Energ í and a, 2016; Rodríguez Maure et al., 2021).

Table 1 .
Recorded data for simulating urban spaces in the selected residential groups.

Table 3 .
Design variables and options for optimization analysis.

Table 4 .
Design variables and options for the optimization analysis.

Table 5 .
Design variables and options for the optimization analysis for Residential Group A.

Table 6 .
Design variables and options for the optimization analysis for Residential Group N.

Table 7 .
Design variables and options for the optimization analysis for Residential Group H.

Table 9 .
Design optimization analysis for Residential groups G 90-G180.

Table 14 .
Arrangement of Internal PMV of urban residential groups according to design preference in achieving internal thermal comfort.

Table 15 .
Energy Efficiency of Residential group H with different orientations.

Table 16 .
Energy Efficiency of the Residential group N with different orientations.

Table 17 .
Co2 emissions for the optimization analysis.