Site, Orientation and Vegetation

As the surrounding physical elements can have positive or negative impacts on the site, as well as on the landscape, they should be considered and spread in a way that promotes PDS. Panagopoulos (2008) claimed that one of the main conditions which makes the space function successful or not is microclimate, as presented in Figure 4:2. To be accurate,

the landscape should be considered as a part of PD. This can have a clear impact. This can be achieved through providing landscape such as trees which can affect the amount of sunlight accessing the building. The architect should consider spreading the landscape over three sides

[west, south and east] to provide shading in the summer to protect the building from heating gains. The tree spread should be suitable in both summer and winter (United States Department of Energy, 2000). This is in terms of the seasons. However, at a daily level the trees should block the low sun during the day to reduce the cooling load. This demands the provision of suitable trees in terms of the size and location in a way that enhances functions. The trees can affect the microclimate of the build- ing through affecting day lighting performance. For this reason, it has been confirmed that there is a need to analyse the microclimate around the space and the residential area (Hongbinget al, 2010). Panagopoulos (2008) referred to the importance of considering plants and trees, as both can affect and help to provide PH to the space as well as save energy. The trees can have two important roles protec- tion from solar and providing shading. The evaporated trees help to decrease the urban temperature. 80% of buildings in hot and humid climates are affected by shade from trees which cools the building (Shashua et al, 2000). Of course, this will only happen if the designers consider the tree locations and numbers. This will lead to an increase in the efficiency of indoor air quality and ensure that trees are not obstacles or burdens on the site. In some cases, their distribution can lead to improving the view of the building. Shashua et al (2000) and Hongbinget et al (2010) claim that it is important to have an

Figure 4:2: The effect of the landscape on sun collection (Panagopoulos, 2008)

accurate analysis of the area surrounding the space in terms of landscape, whether the site has already been landscaped or not.

The relationship between the indoors and the out- doors can have a positive impact on the PDF. It is confirmed that the building can be protected from the hot sun by self shading (Nikolopoulou et al, 2001). The landscape design can provide PH through optimising the quantity of wind or sunshine or shading which of course mitigates the temperature.

Building Information Modelling (BIM) (2011) confirmed the importance of accurately positioning plants to avoid obstructing the air flow; at the same time, this can control the air flow. Providing land- scaping can create interoperability between the EU and the outside and enhance their interior indoor comfort in various ways, as Ahsan (2009) claimed. It is said that using the landscape can lead to re- ductions in noise and pollution, reduce energy consumption, mitigate the “temperature degree and relative humidity”, and finally enhance the EU psychologically (Ahsan, 2009). This means to accu- rately landscape plants and trees to be suitable for the EU. The interoperability between the landscape and EU which has been referred to can lead to optimising the PDF and guaranteeing that it is provided as it is required. Providing landscaping can lead to providing interior comfort.

Lechner (2009) identified that the suitable place for trees in the majority of countries is on the di- rections north, east and west as shown in Figure 4:3. This is in cases where trees are available, but if they are not, they can be replaced by other methods such as bushes, trellis and vertical fins; these methods can be effective on east or west aspects. These methods will affect PV by controlling the wind direction as well as providing shade. Installed fountains or water pools can create cooling air. A vegetative roof is one of the approaches that can cool the air breezes. This approach is mainly used in hot climates. The role of trees is not only to prevent sun radiation but also reflection of some rays coming from surrounding areas such as building surfaces and the sky (Oke, 1989). For this reason, there are many limitations that can affect the PL such as the distance between the building and the trees, the size of the trees, the height of trees and so on. The availability of trees at the urban level can affect air temperature at different levels from the street

trees to the larger boundary. The level of the effect de- pends on the extent of the interoperability between trees and other urban environment elements. At the building level, the tree should accurately follow the hierarchy of building level, site level and urban level. The distance between the trees on a street can have an impact on the

Figure 4:4: The various positions of trees in the case study (Akashi et al, 2006)

Figure 4:3: Distribution of trees (Passive Solar Industries Council, National Renewable Energy Laboratory, and Charles Eley Associates, 1994)

street as well as if there are other trees in the garden of the building. Finally, with regard to the highest trees and build- ings, each of these situations should be considered separately and accurately in order to be located as pillars for optimum PV and not as obstacles to it.

Akashi et al (2006) evaluated one building to see the ef- fect of landscape (tree) on interior cooling of the building

(natural ventilation). Three situations were assumed to measure it. The authors assumed that the build- ing had no surrounding trees in the first case. In the second case, the trees were around the building in two positions, as shown in Figure 4:4. One of the findings was that the position of trees around the building affects the cooling load. For this reason, considering the design of the microclimate around the building is essential to gain the benefit of PV (Akashi et al, 2006). This gives another indicator for designers, which is to accurately assess the circumstances of the site in terms of landscape during the design process. As has been mentioned above, the distribution of landscape strategies should be opti- mised. In the layout of the building, using gardens can affect

the performance of cooling inside the building. Hence, cool and shady places are provided in the summer time. Many landscape factors such as trees, flowerbeds, vine trellises, and soft ground surfaces can be interoperable with the cli- mate and human factors to create comfort both inside and outside the buildings (Brown and Gillespie, 1995).

In both cold and hot climates, the green roof has rapidly

become a consideration in building design. In contrast, in a cold climate, the green roof’s purpose is to store and filter the rain water (Panagopoulos, 2008).The green roof has been installed in different countries around the world as a solution for PH and PV as well as for aesthetic views, as shown in Figure 4:5. ARUP (2012) referred to other positions for landscapes, such as providing landscaping on the courtyards and roof. For the latter, the best example is ACROS Fukuoka in Japan as shown in Fig- ure 4:6 - the serene green roof of Japan. Each of them can play a clear role in PD, when the green elements are accurately positioned. This is interoperability between the EU of space and the land- scape, whether on the outside or the inside of the building, and several authors have indicated this relationship. Hartig (1991) confirmed that a green roof can provide psychological benefits for EUs at an urban level. It also helps to offer visual comfort and reduce EU stress. However, when the designer offers interoperability between the green area and the space, this will make the space more attractive, and might enhance EU productivity. Brown et al (1995) declared that there are different reasons to provide landscapes in the area and space. One of these reasons is to create thermal comfort for EUs. It is also claimed that achievement of thermal comfort for the EU at the landscape level can be when the energy lost is equal or nearly equal to that which is received. For this purpose, thermal comfort is a

Figure 4:6: ACROS Fukuoka: The serene green roof of Japan (Kumar, 2008).

Figure 4:5: Roof Garden (Punggol Roof Garden, 2003).

complex process and it cannot be controlled easily. For instance, the heating sources in the space are different, such as EU, the outside and the interior space. The main challenge when adopt- ing landscaping is how to make a balance between each of them where neither surpasses the other.

The orientation of the building should also be optimised to the prevailing wind and solar access, which of course should be based on the previous investigation and site analysis. The orien- tation of buildings is indicated by several authors. The United

States Department of Energy (2000), BIM (2011) and the Ministry for the Environment (2008) said that the building placement should be accurate for maximising solar access and ventilation strategies. It is added that the changes in the seasons should also be considered, such as in the summer the solar access should be minimised, and maximised in the winter. For this reason, the building location and features should be compliant with the changing seasons.

Optimum orientation can be through orientating the building’s long axis to the south to benefit from solar access and the prevailing wind will be from the west. Jefferson (1789, p.113) defined ori- entation as "an action step permitting passive design features and non-mechanical measures to conserve energy, utilize solar energy for thermal gain, and direct prevailing winds for natural ventila- tion and cooling". This definition covers the main function of orientation and the similarity with the aim of PV. The location and orientation of the building should be considered because any direction has its level of temperature, as Crobu (2010) classified as follows and as shown in Figure 4:7. The south facing is the most suitable position and best orientation; the east is possibly cold in winter and pleasant in summer; the west has high temperatures dur-

ing summer; and finally the north has the coldest wind during winter.

Several authors confirmed that the south orientation is one of the essential indicators of which to take advantage if it is possible. Fernandez-Gonzalez (2007) considered that the largest elevations should be to the north and south to reduce the thermal transmittance and to increase optimum solar collection. Norton and Christensen (2006) discussed the Habitat for Humanity home near Denver, Colorado: this case study has shown the need to consider orientation to the south, and they showed the long façade

was to the south. This is to benefit from the natural environment. The size of opening is increased on the south more than on other façades, as will be shown in Figure 4:8.

Figure 4:7: Various site orientations (Crobu, 2010)

Figure 4:8: South facade (Norton and Chris- tensen, 2006, p.2 and 4)

Orientation to the south at 30 degrees has been indicated by many authors such as the United States Department of Energy (2000) and Badescu et al (2011) to be the suitable degree. The latter indicated the first PD in Romania which was oriented to the south at a 30 degree angle. Different places were grouped to the south orientation. The south façade was the longest as well as having the largest num- ber of windows, as shown in Figure 4:9.

It has been confirmed through analysis that the highest achievement of day lighting in the orientation of school classes is when the large axis is in both north and south orientations and the exposure is both west and east (Kruger

and Dorigo, 2008). The south and north are more preferable than east or west because the sun is very low in the east or west, for that reason a south orientation is preferred (Baker and Koen, 2002). This demands accuracy in the site analysis. Matthias and Amato (2009) claimed that each building has dif- ferent façades in different orientations. The optimum orientation in various climates can be north and south orientation which means the long façade will be on those sides with minimal parts of the build- ing facing to east and west. This case will not always be in the warm climates. The best prevailing wind orientation is to north and south which means the prevailing winds will be from those sides. Garcia-Hansen et al (2002) in their case studies considered that buildings that do not face north are not desirable, as well as considering the obstacles of the day lighting on the northerly façade and the poor design in terms of PDS. The case studies were in Argentina. The location of the building can de- termine the best orientation. It has been confirmed by Li et al (2006) in Hong Kung that the suitable way to face is to south and south-east because the

amount of day lighting is more than on other faces, which means that facing south and south-east is more favourable for both designers and people using the building. This indicator explains the extent of the interoperability between the PL and EU and to what extent they should be interacted together.

Ekici and Aksoy (2008) assumed three rooms with different façade areas to simulate to what extent orientation can affect heating and cooling areas. The result was façades 1/1 and 1/2 achieved the most gain in heating during the period of the study. In contrast, the large faces of both north and south fa- çades were the reason behind the gain of sunshine.

There is interoperability between the orientation of buildings and the site where the placements of buildings can benefit from natural environmental effects such as sun and ventilation. This will be by distributing the buildings on the site (US DOE, 2001). One of them will benefit from PV by different

Figure 4:10: The distribution of the building on the site (US DOE) (2001)

Figure 4:9: Perspective and south eleva- tion of AMVIC office building –Romania

orientation measures to the south and north. The distribution of the buildings on the site should be accurate in a way to ensure benefits from the solar energy and wind direction. Separate buildings on the site will increase the opportunity of benefits from the wind and other natural resources, as pre- sented in Figure 4:10. This distribution could be part of compliance of the design to benefit from the environmental conditions. Jiang and Chen (2002) pointed out that the pre-

vailing wind is from the north side and the northwest direction. The measurement was in the experi- mental period for a site located in the south of Japan. As stated above, the north direction received the prevailing wind; therefore, the largest and widest façades were to the north and south to gain the bene- fit of PV and PL.

There are many limitations of PV that can affect optimisation of PDS functions such as the sur- rounding buildings; in some cases it may be an obstacle of optimising PDF. During studies of wind direction on sites, Hoof and Blocken (2009) said that the urban environment must be taken into ac- count in order to accurately produce PDS. This was the result of

analysing the effect of surrounding buildings which are affect- ing the wind direction. The case study was Amsterdam Stadium and its surrounding area, as shown in Figure 4:11. In this case study, the surrounding area contained high rise buildings, which can be obstacles to the wind direction. The designer should con- sider the current condition and expected condition of the

surrounding area in order to obtain the benefits over a long period of time. This will be to create in- teroperability between the main construction site and the current surrounding buildings as well as any expected buildings. This is not the general case. In cases when the surrounding building is lower than the building which needs to be ventilated, there are numerous factors that can be considered such as the location of the building, or the part of the building which demands the ventilation, e.g., if it is at the same level or higher than them.

In some cases, other factors on the site can affect the PV. For instance, air pollution and noise, es- pecially if the buildings are located in high activity spaces like the centre of a city. However, buildings in suburban areas are preferred to houses in the city in terms of the neighbourhood being cleaner and less dense (Tantasavasdi et al, 2001). Lower density of housing or buildings leads to reduction of the air pollution due to less use of cars, on the one hand. On the other hand, the majority of buildings in suburban areas are separated, which is suitable for accurate application of PDS. The University of Newcastle’s Design Faculty building is a good example. It was oriented to take advantage of PV and prevailing breezes as shown in Figure 4:12 (Prasad and Fox, 1996).

Figure 4:9: Impact of the surrounding buildings (Hoof and Blocken, 2009)

Figure 4:10: The site of the Design Faculty building at Newcastle Univer-

There is another function that should be considered when ori- entating the buildings, which is the outside view (BIM, 2011). This is to enhance the EU comfort. The challenge for the designer is how to provide and interact the view and the environmental conditions when orienting the building. Another challenge should be considered and sometimes could be restrictive, which is the infrastructure and local conditions. For this reason, the designer should adequately consider orientation and building location with the current conditions (Ministry for the Environment, 2008). Op-

timum orientation was traditionally considered. This can be seen clearly in traditional cities when they used wind catchers or other techniques from long a time ago (Department of Education, Northern Ire- land (DENI) and corp creator, 1998). These strategies cannot work without the right orientation or investigation of the climate.

Site analysis is the first stage which the designer should consider in order to achieve the most suit- able orientation and location. The accuracy of site analysis, to find out how the site would benefit from its natural environment, can help the designer to optimise the other design functions. This can be achieved through creating interoperability between three themes: site analysis, landscape, and orienta- tion. The ideal interoperability between these themes can lead to maximising benefits from the natural environment such as solar access and prevailing wind. Both of them are the main feeders to the suc-