Environmental Control in Architecture by Landscape Design

ITU A|Z • Vol 15 No 2 • July 2018 • 197-211 Environmental control in architecture by landscape design

Nazire Papatya SEÇKİN [email protected] • Department of Architecture, Faculty of Architecture, Mimar Sinan Fine Arts University, Istanbul, Turkey

Received: April 2018 • Final Acceptance: July 2018

Abstract The landscape design is a significant component of effective building design. Landscape elements can provide such benefits to buildings as shielding them from the sun, protecting them against wind, facilitating passive cooling, and providing opportunities for natural ventilation. Furthermore, landscape elements can be useful to clean the air and water, absorb floodwaters, improve aesthetics, provide recreational amenities and develop ecological habitats for wildlife. The heating, cooling and lighting of a building are very much affected by the site and landscape in which the building is located. Plants are immensely useful in the heating, cooling and lighting of buildings. Landscaping that sup- ports the heating, cooling, and lighting of buildings varies with the climate. The general logic for tree planting around a building includes shade trees on the east and west, wind breaks on the north, and open fields on the south-facing sides. In this connection, lawns should be used only when necessary. On the other hand, a vertical vine-covered trellis is very effective on east and west facades, while a horizontal trellis can be used on any orientation. Outdoor shading structures such as trellises and pergolas, can be used for providing shade and/or to control air movement. Oth- er functional landscaping elements include allées, pleached allées and hedgerows. In short, the following sections discuss some of the critical concepts and topics necessary for understanding landscape design as it relates to sustainable building design.

Keywords Landscape design, Building design, Landscape elements, Shading structures, doi: 10.5505/itujfa.2018.90022 doi: Windbreaks. 198

1. Introduction priate to cut them down to improve the The architectural design of a build- solar access. The summer shade from ing has a tremendous effect on the heat- mature plants might be more valu- ing, cooling and lighting of a building. able than the last energy from the sun. In fact, when an architect starts to de- However, in most climates, the energy sign the appearance of a building, he/ from the sun is too valuable not to use. she is simultaneously starting the de- Every square meter of the south façade sign of the heating, cooling and light- and south-facing roof should be used ing. In this connection, plants are also to collect daylight, photovoltaic elec- immensely useful in the heating, cool- tricity, and hot water all year long and ing and lighting of buildings. Although passive solar in the winter. plants are very popular, they are usual- On the other hand, evergreen plants ly used for their aesthetic rather than can be used on the east, west and north functional benefits. Ideally, along with sides of a building. These plants are their decorative function they could act most appropriate for protecting against as windbreaks in the winter, as shading the cold winter winds. To provide con- devices and evaporative coolers in the tinuous shade or to block heavy winds summer, and as light filters all year use evergreen trees or shrubs. The best long. Plants can also reduce erosion, windbreaks block wind, close to the noise, dust and other air pollution, the ground by using trees and shrubs that level of carbon dioxide, and increase have low crowns. the level of oxygen in the local air. Through the proper location and In that case, buildings can be com- selection of plants, well-designed land- bined into landscaping techniques scaping can reduce winter heating and that promote the heating, cooling and summer cooling costs of a building as lighting of buildings. The shading from much as 25 percent (Lechner, 2015). plants depends on the species, prun- Plants can also improve the quality of ing, and maturity of the plants. The daylight by filtering and diffusing the best shading devices are the deciduous light and heal human health and per- plants, because they lose their leaves formance. in response to temperature changes. A landscape design is often based Other advantages of deciduous plants on the mature size of plants, thus the include low cost, aesthetically pleas- growth rate is very important. Choos- ing quality, ability to reduce glare and ing a fast-growing plant is not always a ability to cool the air by evaporation good choice, because most fast-grow- from the leaves. On the other hand, ing plants have poor strength. How- the disadvantages of deciduous plants ever, some vines can be the ideal are slow growth, limited height and fast-growing plant for landscaping. the possibility of disease destroying the They are supported on a man-made plant. In general, the east, southeast structure such as a wall, a trellis, a per- and southwest sides of buildings are gola or a table network. These vines are the best locations for deciduous plants. very effective sun shading devices. Unless carefully placed, deciduous Proper use of trees, shrubs, vines plants on the south side of a building and man-made structures can modify may do more harm in the winter than the climate around a building to reduce good in the summer. However, decid- heat gains in summer and heat losses uous plants without their leaves still in winter. Plants can protect a build- block a significant amount of sunlight. ing from winter winds and shade it Furthermore, if the roof has col- from summer sun. Vegetation around lectors for domestic hot water, pool a building can regulate solar radiation heating, and /or heating, and/or pho- during different seasons of the year. tovoltaic, it should also not be shaded Proper building design and landscap- in the summer. Thus, on the south side ing control noise, air pollution, winter of buildings, plants should usually be wind and summer sun. kept below the solar access boundary. The design of landscape elements If large plants already exist on the south such as trees, shrubs, vines and man- side of a building in very hot climates made structures is a significant com- with mild winters, it may not be appro- ponent of effective building design.

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Landscape elements can provide such Annuals and biennials are only herba- benefits to buildings as shielding them ceous; perennials can be either herba- from the sun, protecting them against ceous or woody. Some woody perenni- wind, facilitating passive cooling, pro- als are not totally hard in cold climates viding opportunities for natural ven- and act like herbaceous perennials. tilation, cleaning the air and water, There are a variety of characteristics improving aesthetics, and developing by which to describe or classify plants ecological habitats for wildlife. and distinguish them from one another. Among these, growth habit, season- 2. Landscape concepts al persistence, and ecological origin are Before discussing landscape design particularly important with regard to techniques, some general comments sustainability. about plants are important. The selection of proper plant material requires 2.1. Growth habitat knowledge of concepts such as growth Growth habits define the shape or habits, origin, species` adaptations, form of the plants and play a key role in and plant biological processes. It is also both their aesthetic character and their important to have a comprehension of function in the landscape. Based on contextual topics, including local and growth habit, plants can be classified as global hydrologic systems, precipita- trees, shrubs, groundcovers, or vines. tion, seasonal temperature fluctua- The boundaries between these growth tions, wind, and geography. Some of habit types are not always distinct, nor the critical concepts and topics nec- consistent. A plant species may fall into essary for understanding landscape several categories depending upon the design as it relates to proper building conditions of a particular site or its design are discussed as follows (Car- maintenance regime. Despite the short- penter & Walker, 1998; Marsh, 2010; comings of this classification system, it Vassigh at all, 2013). is widely used in landscape design. Landscape plants are herbaceous plants and woody plants. Herbaceous 2.1.1. Trees plants do not produce woody stems Trees are the largest plant elements and are known botanically as herbs. used in landscape design. It can gen- They may have an upright, prostrate, or erally be defined as a plant which is viney growth habit. Woody plants can taller than 3m. Trees measuring 3 to 6 be classified as trees, shrubs, or woody m is height can be classified as `small vines. The distinction between trees trees`, trees 6 to 9 m can be considered and shrubs is not always apparent. as `medium trees`, and trees taller than Generally, trees are characterized by a 9 m can be considered as `large trees`. single upright stem or trunk, whereas shrubs have several stems. In addition, 2.1.2. Shrubs trees usually are taller than shrubs. The Shrubs are relatively smaller plants distinctions, however, may be obscured than trees. They can be defined as be- by pruning, training, or environmental ing larger than 0.5 m, but less than 3 m conditions. in height. Among woody plants, a major distinction is made between deciduous 2.1.3. Groundcovers plants, and evergreen plants. Ever- Groundcovers are low-level un- green plants are classified as either derstory plants that are grown over broadleaved evergreens or needle ever- and cover an area of ground, acting greens. Conifers constitute the needle as a base layer in a planting design. A evergreen group. groundcover is utilized to provide pro- Plants may also be classified on the tection from erosion and drought, and basis their life span. Annual plants to improve the aesthetic appearance complete their life cycles in one grow- of a landscape by filling areas between ing season and must be planted anew large plants and trees. Plants used as each year. Biennial plants complete groundcovers typically grow to less 0.5 their life cycles in two growing seasons. m tall or are maintained at that height. Perennial plants grow year after year. In general, they reach 15-30 cm high.

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2.1.4. Vines 2.3. Ecological origin A vine is a plant that spreads exten- The ecological origin of a plant is sively along the ground, over the plants typically considered to be the location and objects, or up vertical surfaces. Vines from which a plant species originated. are climbing and rambling plants. They A plant that originates from the local are used on man-made structures such ecology is called native or indigenous. as a trellis, a pergola, a balcony to protect A plant that is not from the local ecolo- from summer sun the horizontal and gy is non-native. vertical planes. Various vines can also be Native plants are well adapted and used for an effective erosion control. integrated into their native ecologies, they tend to be supportive of these 2.2. Seasonal foliage persistence ecologies. These plants can be the food The term seasonal foliage persistence source for native insects and native describes plant species’ annual reten- birds. Using native species in a land- tion of foliage, that is leaves or needles. scape also tends to consume fewer re- Some plants periodically drop their sources because the native plants typ- foliage during a portion of the year, ically don’t require much maintenance while other plants keep their foliage or irrigation relative to non-natives. throughout the year. The differences The use of non-native plants in a land- between plant species’ foliage retention scape design is unlikely to contribute to patterns can have significant impact on the native ecology and in some instanc- their functionality in shielding sun and es may hinder or cause damage to it. wind. Therefore, foliage persistence is an important consideration in the se- 3. Landscaping lection of plants on a site. Well-designed landscaping can make a significant difference in the 2.2.1. Deciduous plants amount of energy required to main- Deciduous plants are those which tain a comfortable building. Proper use completely or significantly, shed their of trees, shrubs, vines and man-made foliage during the winter or dry season, structures can modify the climate and remain bare for a period of time, around a building to reduce heat gains followed by the growth of new leaves in summer and heat losses in winter. in the next growing season, typically Plants can protect a building from win- spring. The shedding of leaves by de- ter winds and shade it from summer ciduous plants allows them to avoid sun. In fact, heat exchange in a building cold damage and to conserve more occurs through three major processes water during dry periods. During the as air infiltration, heat conduction and process of leaf shedding, the leaves of transmission of solar radiation (Walker the deciduous plants can merely dry & Newman, 2009). up and drop off or they may display The first heat exchange process in air a wide array of colors before they are infiltration is the passage of outside air shed. Depending on the species, the through cracks around windows and leaves may turn a bright yellow, a dark doors or other openings in building burgundy, or one of a variety of tones. walls or ceilings. Air pressure on surfaces that face the wind are subject to 2.2.2. Evergreen plants increased air pressure as wind veloc- Evergreen plants retain foliage ity increases. Air enters the building throughout the year. However, some through openings in these surfaces. In evergreen species grow leaves con- winter, heat losses due to air infiltra- stantly during the same period that old tion may represent up to half of the to- leaves are simultaneously shed. All of tal heat losses on the windiest, coldest these plants have special leaves that are days. Properly placed plants can reduce resistant to cold and/or moisture loss. air infiltration by reducing wind veloc- Evergreens may continue to photosyn- ity near the building. thesize during the winter or dry peri- The second heat exchange process od. Depending on the species, foliage is heat conduction through materials colors vary widely and include yellows, from which the building is built. The reds, purples and silvers. amount of heat conduction depends on

ITU A|Z • Vol 15 No 2 • July 2018 • N. P. Seçkin 201 the insulating property of the building cause of the multiple layers that are materials, thickness of materials, and ventilated and because the leaves stay the temperature difference between the cool by the transpiration of water from inner and outer surfaces of the build- the leaves. Transpiration cools not only ing. Landscaping can help control the the plant but also the air in contact temperature difference between the with the vegetation. Thus, the cool- inner and outer surfaces of walls and ing load on a building surrounded by ceilings, and thus reduce heat conduc- trees or grass will be smaller than on tion. The outer surface temperature is a building surrounded by asphalt or controlled mainly by outside air tem- concrete. Trees are more effective than perature, wind velocity and solar ra- grass in providing comfort. Usually the diation. In summer, trees and shrubs best plants to use are native varieties can reduce the amount of solar radia- that have adapted to the local climate, tion reaching the outside surfaces of a soil and pathogens. Thus, less water, building, and thus reduce heat conduc- fertilizer, and chemicals are needed for tion into the building. In the winter, so- healthy plant growth. At night, trees lar heating can reduce the rate of heat work against natural cooling by block- loss by raising the outside temperature ing long-wave radiation. There will be of walls. Blocking cold winter winds more radiant cooling in an open field also reduces conductive heat loss. than under a canopy of trees. The third process for heat exchange Plants can also improve the quality in a building is transmission of solar of daylight entering through windows. radition through windows. Large ex- Direct sunlight can be scattered and panses of east or west-facing glass ad- reduced in intensity, while the glare mit undesirable solar radiation in the from the bright sky can be moderated summer. Large expanses of south-fac- by plants. Vines across the windows or ing glass can help heat a building in trees farther away can have the same winter. Vegetation around a building beneficial effect. can regulate solar radiation during In recent years, vegetated green roofs different seasons of the year. In fact, have become very popular, but for re- solar radiation has significant impact ducing the cooling load on a building, on building. The extent of this impact vegetated green walls are often more is dependent upon several factors, in- effective. Plants are most helpful on cluding building orientation, architec- the east and west walls, which are ex- tural form, materiality and landscape. posed mostly to the summer sun. The The heating, cooling, and lighting of north wall needs the least shading, and a building are very much affected by the south wall’s shading needs depend the site and landscape in which the on the building type and climate. The building is located. Plants are im- plants can also help shade the east and mensely useful in the heating, cooling, west windows. Shading south windows and lighting of buildings. Through the with plants on buildings that need win- proper location and selection of plants, ter heat is a challenge because even de- well-designed landscaping can greatly ciduous plants shade a great deal. reduce energy consumption of a build- On the other hand, the proper choice ing. Plants promote heating primarily and positioning of plants can greatly by reducing infiltration and partly by improve the microclimate of a site. The creating air spaces next to buildings, selection of these plants is very import- which act as extra insulation. Shading ant. In this connection, advice should of a building’s surfaces during periods be obtained from such sources as local of the most intense solar radiation, nurseries, foresters, agriculturists and particularly in hot climates and sea- landscape architects. sons, can be highly effective in reducing excessive thermal heat loads on the 3.1. Landscaping elements building. Simple strategies utilizing landscape The shade from tree is better than planting elements such as trees, shrubs, the shade from a man-made canopy groundcovers or vines in key locations because the tree does not heat up and and in proper quantities can greatly reradiate down. This is the case be- reduce energy consumption. Appro-

Environmental control in architecture by landscape design 202 priately utilized landscape elements and systems can deflect and diffuse sunlight or dissipate solar heat energy to moderate thermal loads and reduce requirements for mechanical cooling (Walker, 1991: Haque, et al., 2004: Kachadorian, 1997).

3.1.1. Shading created by plants Shading of a building’s surfaces during periods of the most intense solar radiation, particularly in hot climates and seasons, can be highly effective in reducing excessive thermal heat loads on the building. Important to the effectiveness of canopy shade is the proper location of trees and shrubs on a site. The most effective shading arrangement for reducing maximum air temperatures and hastening ear- Figure 1. Effect of deciduous trees in ly evening cooling is by shading a summer and winter. building’s roof and its southwest- and west-facing walls and windows. Shade the south-facing roof and wall surfaces that receive the most direct sunlight during midday when the sun is higher in the sky. Also, place plants to shade walls that face generally east or west. These walls receive direct sunlight in the morning and afternoon. In landscaping, deciduous trees and shrubs can be used to block summer sunlight and also allow winter sunlight to reach the building (Figure 1). Plant- ing tall trees with elevated branching structures, or trimming up branches, will also allow more winter sunlight to reach a building as the sun is crossing the sky at a lower angle. Shading other Figure 2. Allées for creating shade and/or portions of a building and its adjacent controlling air movement. site can also help to reduce ambient air temperatures around the building as high bushes or a vine-covered trellis or well as indoor temperatures at some pergola can be used. A newly planted degree. Trees planted at distances too vine will provide shade much soon- far to shade a particular building’s er than a newly planted tree. Pergolas façade surfaces away also help reduce without plants must be carefully de- the air and ground temperatures sur- signed if they are to provide effective rounding the building. Site planting shading. A vertical vine-covered trel- can also help to diminish the light lis is very effective on east and west reflected toward a building from sur- facades, while a horizontal trellis can rounding surfaces. be used on any orientation. Bushes On the other hand, the locations can act as vertical fins to block the low of trees on a site, the impact of cano- sun on north façades. On east and west py shade on moderating heat load is windows, only the bush on the north significantly affected by other factors side should be used if winters are cold. such as trees height and canopy spread. Other functional landscaping elements When trees are not available to shade include allées created by bushes or by the east, west, and north windows, trees (Figure 2).

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the outermost low of planting, downwind, along a line following wind direction. The higher the windbreak, the larger the wind shadow or protected area. Trees or shrubs in a windbreak should be closely spaced to provide a continuous barrier to winds. Design and composition of the windbreak depend on the space avail- Figure 3. A windbreak can shield the building from prevailing able and the species and size of trees. winter winds. Where space is limited a single row of evergreens is adequate. However, up to five rows of several evergreen species is more effective. Spacing in one-, two- and three-row windbreaks should be 1.80 m between trees. Consider the mature shape of the tree when developing a landscape plan for a windbreak (Walker&Newman, 2009). Evergreen planted close to the building can further reduce effects of wind. If allowed to develop into a thick hedge, spread- Figure 4. Foundation plantings to create dead air space. ing evergreens in front of the north and east wall provide additional insulation 3.1.2. Windbreaks from the trapped dead air space they An important climatic element to create (Figure 4). be controlled by landscaping is the In short, a one-row windbreak is wind. Windbreaks can be effective in composed of a single linear row of trees controlling wind and its impacts on or shrubs. To be effective, the one-row buildings. These shelter belts are oc- windbreak should utilize densely plant- curred from rows of trees and shrubs ed evergreen that will retain their low- that are planted to reduce wind speed er limbs and foliage. If deciduous trees or redirect wind movement. In a cold are to be used, they should be densely climate, a properly located and effec- planted and have narrow crowns. tive windbreak can decrease air infil- Two-row and twin-row windbreaks tration and heat loss by reducing wind are comprised of two linear rows of velocity near the building. Plant spe- trees or shrubs. A two-row windbreak cies selected for a windbreak should can be composed a single species, a be able to withstand the desiccating set of two species or a mixture of spe- effects of winter winds. Evergreen cies. To be effective, each row of the species should constitute a significant windbreak should be densely planted portion of the windbreak composition as is done in a one-row windbreak. A because they retain wind-blocking twin-row windbreak is composed of mass in winter when it is most need- two rows of trees or shrubs, but planted. An evergreen properly selected and ed adjacent to one another in an alter- placed can divert cold winds from the nating pattern to form a single mass of building and reduce heating costs. Dis- planting. Planting should be of ever- tance from the building depends on green-type trees or shrubs. the tree height. The optimum distance Three-row windbreaks are com- for reducing wind velocity is about one prised of three rows of trees or shrubs. to three times the windbreak height. The three rows should consist of at However, a windbreak can reduce least one dense row of evergreen trees. winds up to a distance of 30 times the The other rows can be deciduous or height of their tallest row, downwind evergreen plantings. There can also be (Figure 3). The effective distance of a frontline row of shrubs for catching a windbreak is usually expressed in snow if necessary. A three-row wind- terms of a windbreak height multiplier, break can have considerably more which is measured from the center of wildlife value than a single or dou-

Environmental control in architecture by landscape design 204 ble-row windbreak with its additional sheltered spaces and the possibility of a greater diversity of plant species. The use of four or five rows in a windbreak can provide an even greater level of protection. Additional rows allow for greater flexibility in the design and in the diversity of species. One or two of the rows should consist of evergreen planting. The windbreak can also include one or more rows of deciduous plants and small shrubs for snow catch, if necessary.

3.1.3. Foundation plantings Foundation plantings are a continuous line of evergreen along the length of the foundation and around the corners of a building, approximately 1.5 m out Figure 5. Landscaping techniques for a temperate climate. from the outer walls (Figure 4). They can be utilized to achieve considerable should be protected away from win- heating and cooling energy savings in a ter winds. Summer breezes should be low-rise building or the lower levels of directed toward the buildings. A pro- a taller building like windbreaks, foun- totypical landscape design for tem- dation plantings are used to reduce perate climate regions could include wind speed around the building. How- the use of high-canopy, high-branch- ever, they are also used to create a buffer ing deciduous trees on the east and of “dead air space” around the building west sides of the building (Figure 5). with slower circulating air, which acts This would allow penetration by the as an additional insulating layer. warming rays of the low winter sun, In the development of an effective but protect the building from the foundation planting scheme, the plants high summer sun with a full summer should never be allowed to grow much canopy. Low-branching evergreen closer to the building than 1.5 m in tree clusters could be utilized to help order to be sufficiently effective. In- ad block cold northwest or northeast dition, planting too close to a building winds during the winter. In addition, can create problems with mildew, fun- the use of dense evergreen shrubs gi, humidity, and insects. on the north, west and east sides can form an insulating air space between 3.2. Landscaping techniques the building and the planting, which The following design cases show would help to reduce heat loss during landscape strategies for solar, thermal winter months. The windbreak on the and wind control and are based on north side of the building should be climate types. These design solutions no further away than four times its illustrate some general principles that height. can be a guide for applications else- Utilizing an overhead trellis ad- where (Bertauski, 2009: Bainbridg & jacent to the southern façade of the Haggarol, 2011: Lechner, 2015; Vassigh building with deciduous vines can pro- et al, 2013). vide additional shade to the building and create a shaded outdoor space for 3.2.1. Temperate climate strategies use in the summer. The use of outdoor To best accommodate the climate paving materials with light colors will conditions of temperate regions, it is lower heat absorption on the site and necessary to consider more substan- help maintain cooler air temperatures tial seasonal variations. It is advanta- around the building in warmer weath- geous to maximize the warming effect er periods. Contrary to their name, of the sun in winter and maximize temperate climates are hot in the sum- shade during the summer. Buildings mer and cold in the winter.

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sides of the building can increase solar protection in the morning and afternoon, and allow air movement under- neath the canopies. It is also important to keep low vegetation away from the building to allow breezes through and to prevent dampness. To maximize air movement, it is important to channel prevailing winds with wind channeling and deflection techniques. Light-colored paving materials around the building can help to reduce glare and heat absorption.

3.2.3. Hot and dry climate strategies The key objective of landscape -de sign in a hot and dry zone is to maximize shade, especially during the late Figure 6. Landscaping techniques for hot and humid climates. morning and late afternoon hours. In this connection, north and south sides should avoid forestation, while the eastern and western directions, shrubs, vines have been placed on the walls and deciduous trees should be implemented. Locating shade trees to the east and west of the building can help to maximize shade. Also, due to the high altitude of the sun in the sky during hot summer months. It is ad- vantageous to locate high-canopy deciduous trees immediately adjacent to the building to maximize shading of the roof. However, care should be given to closely monitor tree roots in order Figure 7. Landscaping techniques for hot and dry climate. to avoid foundation damage when using this strategy (Figure 7). Additional shade trees or a trellis structure with 3.2.2. Hot and humid climate vines on the southern side of the build- strategies ing can help prevent solar heating of Maximizing shade throughout the the south walls. year and encouraging air movement Protecting the east and west sides are the main objectives for a landscape of the building with climbing vines design in a hot and humid zone. Plants growing on vertical structures will help that allow penetration of low-angle to reduce heat gain in the morning winter sun should provide shade to and afternoon as well as cooling the the building and outdoor living spac- air immediately adjacent to the build- es whenever possible (Figure 6). Avoid ing through transpiration processes. locating planting beds close to the In addition, adding water features is building if they require frequent wa- another useful landscape strategy to tering. Should avoid forestation on the cool a building in a hot dry zone. Hot, southern front, in the northern front. dry winds channelized across a water Significant shade structures such as body can produce a cooling effect for wide trellises with deciduous vines on the building, and also deliver needed the north and south sides of a build- moisture, taking advantage of quick ing can provide additional help for evaporation in the dry air. solar protection and form comfortable With regard to site landscape, it outdoor areas. Utilizing high-canopy is preferable to reduce the amount deciduous trees on the east and west of paving and cover the ground with

Environmental control in architecture by landscape design 206 vegetation as much as water resources allow. This significantly reduces the potential for heat absorption by the paved surface and also reduces glare. In areas where paving is necessary, use of light-colored surface materials can help to reduce negative effects. In addition, courtyards and garden walls keep out the hot winds and conserve cool, moist air.

3.2.4. Very cold climate strategies In very cold climate regions, it is very important to protect the building from northern winter winds. Dense windbreaks are used to protect the building from cold winter winds. If summer overheating is a problem, shade south and west windows and walls from the direct summer sun. The north façade is useful in very cold climate regions part- Figure 8. Landscaping techniques for very cold climates. ly raised land application. Northern, eastern and western fronts in constantly reflective material can be incorporated evergreen shrubs and the low branch- into the design on the southern side es of trees should be preferred. In the of the structure. Furthermore, darker southern wind breaker, low shrubs and paving materials may also be used on grass should be applied. In southeast site to capture warmth and promote and southwest direction away from snowmelt. the building, deciduous trees should be used (Figure 8). Forming an earth- 3.3. Vegetated surface systems en berm on the north and northwest In recent years, planting on roofs sides of the building and planting dense and walls is one of the most innova- rows of evergreen trees and shrubs will tive and rapidly developing fields in help to break the speed of the cold win- the world of the built environment. ter wind and create a trap for blow- The use of green roofs is becoming ing snow. Additional dense evergreen more and more frequent, usually on shrubs adjacent to the northern sides of new and innovative buildings. An the building can help to create dead air idea and technology that started in the space, providing insulation during both German-speaking countries of central winter and summer months. Earth Europe is rapidly spreading to the rest sheltering may also be an effective solu- of the industrialized world, including tion in very cold climates. If the build- the tropics. The use of living walls too ing site is located on a south-facing is spreading, both the use of climbers slope that receives sufficient sunlight, and that of plants being grown vertical- an elevational earth sheltering design ly. The contemporary use of plants on can be utilized effectively. roofs and walls is distinguished from Using deciduous shrubs and trees previous uses by the integration of on the south side of a building can planting and its supporting structures provide some summer shading when with the construction of the buildings needed, but admit low winter rays. themselves. It is important to appre- In addition, deciduous, high-canopy ciate the distinction between older trees on the east and west sides of a technologies of plant use and the new. building will allow warm winter rays, Old-style roof gardens either restricted provide summer shade, and promote the planting to containers and planters summer breezes under their canopies. or used a layer of ordinary soil spread To further capture low winter sun and onto a roof surface. Traditionally, roof reflect its warmth to building interiors, terraces and roof gardens consisted of a sunken terrace with a light-colored plants in containers which stood over

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3.3.1.1. Extensive roof greening Extensive is loosely used to describe a system that typically has a very shal- low depth between 2 and 15 cm of soil or growing medium and is primarily used for its environmental benefits such as stormwater management, reducing the urban heat island effect and insulating properties. They can support relatively smaller-sized plant materials (Figure 9). Because of their limitations with plant material sizing, Figure 9. Extensive green roof. this green roof type is more commonly used where weight loads are a limiting factor, such as in cases involving con- versions of existing conventional roofs. It is seldom irrigated; and it is not usually intended to be accessed directly for use as a garden or open space, though paved walkways and seating areas accommodate use as open space as well. Extensive roofs or living green roofs are generally much cheaper than intensive roofs, both in construction and maintenance.

3.3.1.2. Intensive roof greening Intensive roof greening or landscape over structure is similar to the old-style Figure 10. Intensive green roof. roof gardens, where it is expected that people would use the area much as a paved surfaces (Dunnett and Kings- conventional garden. Depending on bury, 2008; Seckin et al, 2017). While the amount of vegetation, most of the new-style roof greening may incorpo- same ecological and environmental rate substantial areas of hard surface benefits may be derived from the con- and be accessible for recreation and struction of landscapes over structures other uses, plants and green dominate as from living green roofs. Where large the roof area. weight loads can be accommodated, an intensive system can be utilized in 3.3.1. Green roofs which the growing medium exceeds 30 New-style roof greening recognizes cm in depth (Figure 10). three main approaches, extensive, in- Intensive roofs can support the tensive and semi-intensive. On a green whole range vegetation types, from roof, vegetation is planted in a growing trees and shrubs through to herba- medium laid over a waterproof mem- ceous planting and lawns. Substantial brane separating the system from the pools and water features are possible. roof and the building below. A green Such roofs are usually intended to be roof may also contain additional layers accessible to people, and certainly need to provide root barrier protection, ir- to look good. rigation, and drainage. The vegetation on a green roof can be composed of 3.3.1.3. Semi-intensive roof greening low groundcovers or may contain large Green roofs are seen as either exten- trees and shrubs, depending upon sive or intensive, but there is no rea- the system`s construction (Weiler & son why elements of both cannot be Scholz-Barth, 2009: Snodgrass & Mc- combined on the same roof. Extensive lntyre, 2010). Green roof systems are and intensive greening techniques can defined as follows. be combined on the same roof. There

Environmental control in architecture by landscape design 208 is great scope for using intensive and semi-intensive techniques on accessible roofs, combined perhaps with larger herbaceous and woody plant material in strategically placed containers or planters to create contemporary roof gardens that are much more sustainable than the roof gardens of the past. In this context, the semi-intensive green roof has a great deal of potential for the creative extension of roof planting where the roof area is visible and intended for human use. Semi-intensive roofs use lightweight substrates Figure 11. Semi-intensive green roof. and modern green-roof construction technologies (Figure 11). Substrate or environment than roof greening, as the growing medium depths are between surface area of the walls of buildings is 15-30 cm, which reduces the amount always greater than the area of the roof. of extra loading that must be built into For example, with high-rise buildings the roof construction. this can be as much as twenty times the Intensive and semi-intensive sys- roof area. tems can accommodate larger plants species, including trees. In general, 3.3.2.1. Vine-covered walls roofs with greater soil depth can bet- For the vine-covered walls, vines ter retain moisture and maintain more may be grown on the ground level stable soil temperatures. On a green or in planters that can be attached to roof, evapotranspiration processes a building at elevated points to reach from plants absorb most solar radia- higher levels. In selecting the prop- tion. This leads to cooler temperatures er plant material for a vine covering, on the rooftop, reducing the heat load an understanding of the local climate on the building. In addition the effects plays a significant role. In cold cli- of evapotranspiration, the plants on a mates, deciduous materials should be green roof offer a buffer for the build- used on south-and east-facing walls, ing from incoming solar energy and which will help in blocking sun in the also an irregular and diffusing surface summer and let sun through during for solar rays to strike. the winter. In hot climates, evergreen vines should be used on the west and 3.3.2. Façade greening south walls. However, care should be One of the most unattractive fea- taken in utilizing vine covering, as tures of much modern architecture is vines adhered directly to a wall can the presence of blank walls without sometimes undermine the integrity windows or ornamentation. The idea of wall materials over time. Utilizing a of growing plants on a substrate at- trellis system can help to overcome this tached to the surface of such walls is an issue (Figure 12). attractive solution. Façade greening is essentially a liv- 3.3.2.2. Living wall systems ing cladding system for buildings. Living walls are more complex than Climbers or in some cases trained vine coverings, but they offer a level of shrubs, are used to cover the surface of increased design control and can be a building. Traditionally, self-clinging instituted more extensively and more climbers have been used, as they re- selectively than vine coverings. Living quire no supporting network of wires walls are engineered systems, typically or trellis. Modern façade greening, composed of many individual plants however, favours the use of climbers that are planted on a vertical support supported by steel cables or trellis. structure. They can be wall-mounted Greening the wall of a building has or freestanding systems. The support potentially more effect on the building structure of the wall may contain plant-

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4. Landscape irrigation Water is an essential life element. Employing proper landscape design strategies plays a significant role in conserving water and reducing the de- mand on potable water supplies. The use of low-irrigation plant materials, efficient irrigation systems, and the expanded use of treated wastewater or harvested rainwater for irrigation can help to achieve significant reductions in water use. The selection of plants materials is a significant component of developing a landscape design that is resource conscious and sustainable. Many plants used in man-made landscapes Figure 12. Vine-covered wall. consume significant amounts of water to remain healthy. Turf lawns, in particular, can be large consumers of water resources and they also require a great amount of maintenance. Mere- ly substituting a lawn with a properly chosen herbaceous plant cover can drastically reduce water use and maintenance in many instances. Large trees can also considerably reduce the irrigation needs of a landscape. But, the best strategy for reducing plant irrigation is to use native plants ideally suited to a site’s conditions, including precipitation levels. In contrast, many non-native plant species may require significant amounts of irrigation and extra care to keep them alive and Figure 13. Living wall. healthy. Using appropriate technologies can ing containers with a growing medium easily improve water-use-efficiency in or fabric planter pockets that contain any irrigation system. There are two plants in a soilless hydroponic system main irrigation systems that are com- (Figure 13). Hydroponic, the technolo- monly used to irrigate landscapes, gy of growing plants without soil using namely sprinkler and drip irrigation balanced nutrient solutions to provide (Figure 14). A sprinkler is a water emis- all the plant’s food and water require- sion device that throws water through ments, is the obvious solution in a sit- the air with a predictable pattern and uation where no water can be held for radius. There are two broad categories very long. Living walls also typically of sprinkler used in landscape as well have an irrigation system. Hydroponic as pop-up spray sprinklers and pop- living wall systems are kept constant- up rotor sprinklers. Pop-up sprays are ly moist through the irrigation system generally suitable for small-radius ap- that provides all the requirements for plications and small or irregular areas. successful growth of the plants. A living Pop-up rotors are suitable for large-ra- wall’s vegetation can be composed of dius applications and larger areas of evergreen or deciduous plant species. turf grass. Drip irrigation is commonly However, the use of deciduous plants applied in landscape shrub beds, trees, may expose the underlying structure of and potted plants and the like and uses the living wall, which may not be desir- water emission devices called emitters, able for aesthetic reasons. which have low flow rates. Emitters are

Environmental control in architecture by landscape design 210 available in single-outlet or multi-outlet models (Smith, 1997: Melby, 1995: Seckin, 2003, 2011 in press).

5. Conclusion The architectural design and landscaping have a tremendous effect on the heating, cooling and lighting of a building. In that case, buildings can be combined into landscaping techniques. These techniques can reduce a building`s energy requirements during all four seasons, by blocking out the hot summer sun, encouraging warming solar radiation in winter, deflecting cold winter winds and channeling breezes for cooling in spring, summer and fall. In reducing the amount of cooling energy required by a building, landscaping may be useful by directly shading the building with trees, shrubs or vines, shading the area around the building to lower the temperature of its surroundings, and using ground covers to reduce sunlight reflected into Figure 14. Types of irrigation systems. the building and lower the surrounding ground temperatures. In this con- these sides since they can both shade in nection, trees should not be planted summer and admit some winter solar closer than 3.0 m or 4.5 m from the gain. building`s foundation. Shrubs are of- Landscaping can also benefit a ten a good alternative for shading walls building in winter by decreasing in- and windows because they grow more filtration. Since higher wind speeds quickly than trees and may be plant- mean higher infiltration rates, planting ed closer to the building since their windbreaks to reduce the wind speeds root structures are less likely to cause approaching the building can lower its damage. Vines may be trained to climb energy needs. Locate the windbreak on wire, trellis structures to provide lo- the windward side of the building in a calized shade in the summer. Be sure way that it does not interfere with solar that there is adequate space between access. Use evergreen trees and shrubs shrubs or vines and the building to al- for windbreaks on the windward side. low air flow and help present mold or If sunlight or a view is important, a mildew formation on the wall. Vines combination of deciduous trees and grow quickly; make sure that they stay shrubs may be used, but this will be on their wire or trellis structure and do less effective. not move onto the building in order to The windbreak should be dense, avoid damage to the siding. rather than solid, because solid wind- For solar systems to work effective- breaks create turbulence behind them. ly, they need to be unshaded between The density of the windbreak should be 9 a.m and 3 p.m solar time. Unfortu- maintained from the ground up with- nately, a tree extends into the solar ac- out major gaps. A mixture of various cess zone and causes shading depends shrubs and trees can help prevent these upon the height of the tree and its dis- gaps. It is also a good idea to mix spe- tance from the solar collection surfac- cies within the windbreak to avoid the es. The overall energy needs of a build- possibility of losing the entire wind- ing are better met by making sure the break to a disease which affects one east and west sides are shaded during species. the summer. However, high branching Landscaping may also be used to deciduous trees make a good choice for help cool a building by leaving an open

ITU A|Z • Vol 15 No 2 • July 2018 • N. P. Seçkin 211 channel between trees or hedges in the (2008). Planting green roofs and living direction of summer winds to direct walls. London: Timber Press. the breezes on and into the building. Haque M.T., Tai, L., & Ham, D. Unfortunately, channeling summer (2004). “Landscaping design for ener- breezes for cooling is worthwhile only gy effiency”. USA: Carolina Energy Of- if the building`s personal tends to use fice, Clemson University Digital Press. natural cooling practices. Kachadorian, J. (1997). The passive In short, in a strategic landscaping: solar house: using solar design to heat • Shade the east and west faces of & cool your home. Second edition. Ver- the building, giving top priority to mont: Chelsea Green Publishing Com- the west side, and giving priority pany. to shading windows over shading Lechner, N. (2015). Heating, cooling, walls. lighting: sustainable design methods for • Avoid shading of surfaces to be architects. Fourth edition. New Jersey: used for solar collection. John Wiley & Sons, Inc. • Shade the area surrounding the Marsh, W.M. (2010). Landscape building. planning environmental applications. • Cover bare ground with lawns or Fifth edition. New York: John Wiley & other ground covers rather than Sons,Inc. paving where possible. Melby, P. (1995). Simplified irriga- • Plant to provide a channel for sum- tion design. Second edition. New York: mer breezes, if natural ventilation is John Wiley & Sons.Inc. used, and if it doesn`t conflict with Seçkin, Ö.B. (2003). Peyzaj uygu- planting for a windbreak. lama tekniği. İstanbul: İ.Ü. Basım ve On the other hand, vegetated surface Yayınevi. systems such as green roof, vine-cov- Seçkin, N.P., Seçkin, Y.Ç., & Seçkin, ered wall and living wall are built on Ö.B. (2011). Sürdürülebilir peyzaj the façades and roofs of buildings to tasarımı ve uygulama ilkeleri. İstanbul: protect from solar heat in several ways. Literatür Yayınları. These systems can potentially offer an Seçkin, N.P., Seçkin, Y.Ç., & Seçkin, additional insulating layer to a build- Ö.B. (2017). Yapılarda su ve nem kon- ing, helping to maintain the tempera- trolü, İstanbul: Literatür Yayınları. tures inside, and providing the effective Smith, S.W. (1997). Landscape irri- environmental impact outside. gation: design and management. New In addition to, well-designed land- York: John Wiley & Sons.Inc. scaping has a significant role in con- Snodgrass, E.C., & Mclntyre, L. serving irrigation water. In this con- (2010). The green roof manual: A pro- nection, he use of low-irrigation plant fessional guide to design, installation, materials and efficient irrigation sys- and maintenance. London: Timber tems can help to achieve significant re- press. ductions in water use. Vassigh, S., Özer, E., & Spiegelhalter, T. (2013). Best practices in sustainable References building design. Florida: J. Ross Pub- Bainbridg, D.A., & Haggarol, K. lishing, Inc. (2011). Passive solar architecture: heat- Walker, T.D. (1991). Planting design. ing, cooling, ventilation, daylighting and Second edition. New York: John Wiley more using natural flows. Vermont: & Sons, Inc. Chelsea Green Publishing Company. Walker, L., & Newman, S. (2009). Bertauski, T. (2009). Designing the Landscaping for energy conservation. landscape: An introductory guide for Colorado: Colorado State University the landscape designer. New Jersey: Extension. Publications. no.7.225. Pearson Prentice Hall. Weiler, S.K., & Scholz-Barth, K. Carpenter, P.L., & Walker, T.D. (2009). Green roof systems: A guide to (1998). Plants in the landscape. Illinois: the planning, design and construction of Waveland Press,Inc. landscapes over structure. New Jersey: Dunnett, N., & Kingsbury, N. John Wiley & Sons, Inc.

Environmental control in architecture by landscape design