Utilization of Adaptive Opportunity in Residential Buildings within a Warm-Humid Urban Environment

American Journal of Engineering Research (AJER) 2016 American Journal of Engineering Research (AJER) e-ISSN: 2320-0847 p-ISSN : 2320-0936 Volume-5, Issue-12, pp-193-199 www.ajer.org Research Paper Open Access

Utilization of Adaptive Opportunity in Residential Buildings within a Warm-Humid Urban Environment Adewale Oluseyi Adunola Department of Architecture, Faculty of Art, Design and Architecture, University of Johannesburg, South Africa Department of Architecture, Obafemi Awolowo University, Ile-Ife, Nigeria

ABSTRACT: The focus in the design of buildings in cities must be energy-saving measures for sustainability.

The adaptive nature of thermal comfort can provide a sustainable means of indoor comfort provision rather than dependence on active energy. A thermal comfort survey was conducted on residents of 528 buildings in 12 selected residential areas of Ibadan, a warm-humid city in Nigeria, to examine adaptive opportunity. The adaptive actions most utilized were: drawing of curtain, opening of window, putting on fan and movement to semi-outdoor spaces like verandah, porch and courtyard. The values of mean comfort vote for the respondents expressed better comfort levels than the corresponding values of Predicted Mean Vote. It was established that the adaptive principle was operational within this study context. Some adaptive actions were strongly correlated with adaptive opportunity as exhibited in the building design features and the design typology.

Keywords: adaptive opportunity, adaptive thermal comfort, building design features, sustainability, urban, warm-humid.

I.

INTRODUCTION

The buildings within warm-humid tropical climate have to contend with high values of the environmental parameters of thermal comfort like air temperature, relative humidity and mean radiant temperature. There is usually a build-up of heat in such buildings in the afternoon periods bringing the experience of discomfort for residents. It is of concern that the urban air temperature is gradually rising in all cities of the world, caused by drastic reduction in the green area in cities [1]. It has also been submitted that the outdoor environment is deteriorating especially in tropical cities because of rapid urbanization thereby increasing thermal discomfort [2]. Due to thermal discomfort, many buildings in tropical cities utilize airconditioning with the energy demand increasing daily as well as the negative impact on the environment.

Unfortunately, the use of air-conditioning has the disadvantage of high cost which the poor urban dwellers of developing countries which are mostly located in the tropics cannot afford. Additionally, power generators consuming substantial amounts of fossil fuels are used extensively in a country like Nigeria by both rich and poor alike because of incessant power outage. All these uncoordinated excessive energy use in buildings contribute to global environmental problems like climate change through the release of greenhouse and ozonedepleting gases into the atmosphere.

Environmental challenges notwithstanding, indoor thermal comfort is considered a primary functional requirement of every building. The use of air-conditioning and space-heating for comfort provision, even though of necessity in many circumstances has proved to be negative as far as sustainability of the environment is concerned. The focus in the design of buildings within cities must be energy-saving measures for sustainability.

The adaptive nature of thermal comfort has been expressed as a means of extending the comfort conditions within spaces as occupants utilize the adaptive opportunities available to them. The adaptive principle states that if a change occurs such as to produce discomfort, people react in ways which tend to restore their comfort [3].

The adaptive approach to thermal comfort can be utilized with a view to providing information on the passive design of buildings as a means of attaining sustainability in the built environment.

In the study, a thermal comfort survey was conducted in Ibadan metropolis in the warm-humid zone in Nigeria, to examine the adaptive actions of the residents. The applicability of the adaptive approach in the context of a Nigerian urban residential environment is examined using the indoor thermal comfort experience and the adaptive opportunity.

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LITERATURE REVIEW

Thermal comfort is generally defined as that condition of mind which expresses satisfaction with the thermal environment [4]. The study of thermal comfort is pertinent when considering the functional adequacy of buildings and the sustainability of the urban built environment. The spaces provided within and around buildings are meant to exhibit acceptable thermal environment for enhancement of user satisfaction. It needs to be noted that the existing thermal comfort standards and methods cover mainly thermal comfort conditions under steady state conditions as pointed out in [5]. It is however rare to encounter steady state conditions in existing buildings given the dynamic thermal interactions between the building envelope, the occupants and the servicing systems. It is also evident that the temperature in free running buildings is far less likely to be steady.

From the standpoint of human adaptation, the adaptive approach investigates the dynamic relation between people and their everyday environments. People make adaptations to their clothing and their thermal environment to secure comfort. The adaptive principle codifies the behaviour of building occupants which takes two basics forms: an adjustment to the optimal comfort temperature by changes in clothing, activity, posture and so on to make the occupant comfortable in prevailing conditions or an adjustment of indoor conditions by the use of controls such as windows, blinds, fans and the occupant movements [5] [6].

A description of thermal comfort surveys in Pakistan was given in [7] – one longitudinal, conducted in summer and winter and the other transverse, with monthly surveys over a whole year in five cities. The use of building controls and clothing were examined and found significant to comfort. In the study, there was a definite relationship between indoor comfort and outdoor conditions in line with an adaptive approach to thermal comfort. Limits were found for people‟s ability to adapt to indoor temperatures. Studies on office buildings in some American and European cities pointed out that occupants were more satisfied with indoor conditions in naturally ventilated buildings than air-conditioned buildings [8] [9][10][11].

Newsham assessed the energy implications of having a moving occupant inside an office and stated that there is an effect on comfort and overheating predictions. He found that a moving occupant was 0.2ºC warmer in under heated situations and 1.5ºC cooler in overheated ones than a fixed occupant. The result implied that the moving occupant is more adept to avoiding overheating than avoiding under heating. The speculation was that if passive overheating controls were all available, simulation results indicate that it would be best to encourage the movement option first as it incurs almost no energy penalty on the building[12][13].

Hunn assessed how and why buildings use energy, and how energy use and peak demand can be reduced utilizing Wray‟s equivalent uniform temperature in a non-uniform indoor environment with adaptive opportunity [14]. The impact of adaptive opportunity was stressed in the findings. The study reported the adaptive behavior of occupants having impact and improvement on indoor comfort. The different findings discussed above are in accord and are essentially bringing new development to the study of thermal comfort.

Assessment of comfort limits and comfort standard derivation are now in need of revision [15][16]. The adaptive approach is quite advantageous because of the enhancement of the applicability of passive design. It is a step ahead in the direction of passive and low-energy architecture. This indoor thermal comfort study was undertaken in Ibadan metropolis to examine the adaptive thermal comfort of the residents and the impact of adaptive action and adaptive opportunity.

III. STUDY AREA The study area is Ibadan, an urban centre located on latitude 7023‟N and longitude 3055‟E in the SouthWestern part of Nigeria. The cities of the southern part of Nigeria are within the warm-humid climatic zone. The warm-humid climate is found close to the Equator and extends to 15 o latitude, North and South [17]. It is generally characterized by high temperatures and high humidity. The seasonal pattern is dominated by periods of high rainfall, fairly evenly distributed. There are small diurnal and annual variations of temperature and little seasonal variations. There are light winds and long periods of still air [17]. There are however subdivisions of local areas within this broad warm-humid climate classification. These subdivisions are the continuously humid and the seasonally humid or the tropical wet and the tropical wet and dry climatic subdivisions, all within the warm-humid tropical region.

Ibadan is seasonally humid because of its inland location [18]. While coastal places are continuously humid with rainfall exceeding 1500mm throughout the year, for the seasonally humid climate, the annual and monthly rainfall totals are lower especially during the dry months. The extremes of temperature are greater in the seasonally humid climate than in the continuously humid climate. Relative humidity varies between 50 percent and 80 percent although saturation point is usually approached during the night of the rainy season. In Ibadan, the mean maximum temperature is 31oC, the mean record high temperature is 35oC, the mean maximum relative humidity is 95.7%, the average relative humidity is 81%, the mean radiation is 14.2MJ/m 2/day, the total precipitation is 1121mm and the mean air velocity is 0.72m/s [19]. A study in the city reported that maximum temperature has been on the increase in Ibadan from 30 oC in 1979 to 33.5oC in 2009 [20]. The sequence of weather conditions in Ibadan, as well as in other places in Nigeria and other West African countries during the

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course of a given year actually depends on the location of the place in relation to the fluctuating surface position of the Inter-Tropical Convergence Zone (ITCZ). ITCZ is defined as the belt of low pressure girdling the Earth, near the equator, where the trade winds of the Northern and Southern Hemispheres come together [21].

Ibadan metropolis, the focus of the study, comprises of five local government areas. The selected 12 neighbourhoods for the thermal comfort field survey were the following: Agbowo, Challenge, Aliwo, Mokola, Oke-Ado, Ile-titun, Apata, (7 high density neighbourhoods); Abayomi, Ijokodo, Odo-Ona-Elewe, (3 medium density neighbourhoods); New Bodija, Idi-Ishin, (2 low-density neighbourhoods).

IV. METHODOLOGY A thermal comfort survey was conducted in Ibadan metropolis to examine the adaptive thermal comfort of the residents. Ten percent (12) of the 119 neighbourhoods identified from the metropolitan map were selected by stratified random sampling comprising of 2 low, 3 medium and 7 high residential densities. The total number of houses in each of the neighbourhoods was estimated to be an average value of 885 based on data from [22]. A sample size of five percent of this gave 44 houses in each neighbourhood which were selected using systematic random sampling to give a total of 528 houses for the survey. For each selected building, observation and measurements were used to assess the characteristics in relation to thermal comfort. Indoor and outdoor measurements of air temperature and other relevant climatic elements were done in representative buildings in the neighbourhoods.

Since the subject of the research work was adaptive thermal comfort, it was necessary to carry out the study in one of the months with thermal discomfort as evaluated from climatic analysis. The uncomfortable thermal conditions in the period of discomfort actually induce the operation of the adaptive principle. As discussed earlier, the adaptive principle states that if a change occurs such as to produce discomfort, people react in ways which tend to restore their comfort [5]. The selection reflected the prevailing climatic condition in Ibadan metropolis since it was based on the result of climatic analysis (Table 1). From the climatic analysis, months of hot discomfort with maximum Effective Temperatures greater than 25 oC were February, March, April, May, June, October and November with the afternoon period identified as time of hot discomfort. April had the highest value of ETmax of 26.6oC. The Ibadan climatic data showed that the record highest temperatures Table 1. Climatic Analysis for Ibadan using Monthly Effective Temperatures.

Mean Max DBT RH Min WBT ET Max Mean Min DBT RH max WBT ET Min

JAN 32.5

FEB 34.3

MAR 31.18

APR 31.98

MAY 30.91

JUN 29.07

JUL 27.76

AUG 27.00

SEP 29.20

OCT 30.20

NOV 31.4

DEC 32.5

27.2 19.35 25.00

26.93 20.30 26.00

26.13 20.72 26.40

51.50 23.85 26.60

58.74 24.40 26.50

60.23 23.25 25.30

69.77 23.35 24.70

70.87 24.10 24.60

59.33 22.90 25.00

58.33 23.65 25.80

49.00 22.70 25.90

25.42 18.35 24.7

20.87

21.76

23.11

22.95

22.68

21.18

21.33

21.19

21.12

21.19

22.16

21.68

95.52 20.50 19.50

93.97 21.05 20.40

90.06 21.80 21.50

98.67 23.70 22.20

98.74 22.55 21.60

99.37 20.95 20.00

99.71 21.10 20.20

99.06 21.00 20.00

98.10 20.90 20.00

98.69 22.90 21.25

98.37 21.75 21.00

95.65 21.45 20.50

Legend: DBT – Dry Bulb Temperature WBT – Wet Bulb temperature RH – Relative humidity ET – Effective temperature Of 39oC occurred in the month of February and 38oC in March and April. The mean maximum temperature was highest in February and March (34oC) closely followed by April, January and November (33oC) [19]. From the discomfort months‟ list presented in the climatic analysis, the month of April in 2010 was selected as the month for the survey. The afternoon period was specified as hot discomfort period based on the climatic analysis and therefore given special assessment attention in the study.

For the administration of the questionnaire, an adult member (aged 20 years and above) of a household in each selected house was sampled. The questionnaire elicited information on residents‟ adaptive thermal responses and adaptive actions. The respondents indicated any available adaptive opportunity in the spaces, either from space to space or within the spaces in the study area. For the thermal comfort survey, respondents indicated their adaptive thermal response on a seven-point ASHRAE thermal comfort scale. A modified longitudinal design was used, with one respondent asked to assess the thermal environment in each building.

They specifically indicated any action taken to attain comfort as well as their personal parameters of thermal comfort like clothing ensemble and activity level. A special assessment of the living room space was done in the afternoon period which was considered the period of hot discomfort for the study area as determined from

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climatic analysis. The living room was purposively selected for this because of its assumed prime importance in all apartments.

The Mean Comfort Votes of thermal assessments given by the respondents were determined for the sets of indoor and outdoor air temperatures recorded. Also determined were the respective Percentage in Comfort and Percentage in Discomfort. The Predicted Mean Votes (PMV) and Predicted Percentage of Dissatisfied (PPD) were also determined using the PMV Tool v.2 programmed by [23]. This application is an implementation of ISO 7730-1993 (E) standard procedure for calculating the Predicted Mean Vote (PMV). The PMV model is based on heat balance equations for the human body and is an index that predicts the mean vote of a large group of people on a 7-point thermal sensation scale from -3 through 0 to +3. The Predicted Mean Votes values were compared to the actual Mean Comfort Votes obtained from the thermal assessment.

Correlation was used to examine the adaptive actions and the adaptive opportunities with respect to the design features of the buildings and spaces as well as the design typology and the house type.

V.

FINDINGS AND DISCUSSION

The findings from the study are as discussed in the following subsections.

Analysis of the Mean Comfort Vote of respondents The comparison of the values of actual mean comfort vote of respondents to the predicted mean vote at the respective recorded temperatures in the afternoon period will give an insight into the effectiveness of the adaptive comfort approach. The cross-tabulations of indoor and outdoor temperature values and adaptive thermal responses were used to derive a table relating air temperatures and corresponding mean comfort votes of the responses. Also determined were the Percentage in Comfort and Percentage in Discomfort. The Percentage in Comfort comprised all votes in the „slightly warm‟, „neutral‟ and „slightly cool‟ categories (taken as the comfort zone votes of respondents) as a percentage of the total votes for the respective air temperature values.

The values of mean comfort votes were compared to the Predicted Mean Vote (PMV) values. The comparison of the respective values in Table 2 showed that the PMV was higher than the mean comfort vote of respondents in all cases of recorded afternoon temperature values. This comparative analysis gave an indication that the respondents had a higher tolerance for higher temperatures than what was predicted by the PMV. In other words, the respondents actually felt cooler than the rating given by the PMV at all the considered temperatures.

Table 2. Comparison of mean comfort vote and predicted mean vote values Outdoor Temperature o C 33.9 35.8 36.0 35.6 32.0 32.5 33.4 32.7

Indoor Temperature o C 32.3 34.0 34.2 33.1 32.2 31.7 33.8 33.3

Mean Comfort Vote -0.250 0.941 1.634 0.463 -1.070 0.159 1.087 0.054

Percentage in Comfort 55.36 52.94 33.87 67.07 50.89 70.45 43.71 47.69

Percentage in Discomfort 44.64 47.06 66.13 32.93 49.11 29.55 56.29 52.31

PMV

PPD

2.09 2.85 2.85 2.47 1.87 1.49 2.63 2.25

80.5 98.2 98.2 92.7 70.7 50.6 95.8 86.7

Similarly it was found in the table that the values obtained for the Predicted Percentage in Discomfort (PPD) using the PMV software were higher than the respective values of Percentage in Discomfort determined from the survey results. The implication was that the PMV model rated greater proportion of the population to be in discomfort at the respective temperatures than the actual proportion in discomfort as determined from the field study.

An explanation that can be given for these discrepancies in values and hence faulty predictions from the PMV index with respect to the thermal experience of respondents in this study is that the PMV index assumes a steady state situation which does not exist in reality. Hence it does not account for the impact of adaptive action factors which actually come into play in real life situation. As stated earlier, the adaptive approach investigates the dynamic relation between people and their everyday environments because people make adaptations to their thermal environment and their clothing to secure comfort. The PMV has the input only from the four thermal comfort environmental parameters of air temperature, relative humidity, mean radiant temperature and air velocity as well as the two personal parameters of clothing and metabolism. The difference in the values of the Mean Comfort Vote obtained from the survey and the computed PMV values indicated that the indoor thermal comfort experience of the respondents was modified by the adaptive actions they took.

Consequently, the comfort zone of the respondents widened as a result of their adaptive actions. It can be seen that respondents took self-regulating actions to attain comfort in the study. It is still necessary however to establish relationships between the thermal response of the respondents and the adaptive actions and to know which adaptive actions are highly significant in their influence on indoor thermal comfort.

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Analysis of the Adaptive Actions It is of interest to establish the pattern of use of adaptive actions by respondents in the study. The afternoon period was the period of hot discomfort relevant for the adaptive actions. The adaptive actions taken by respondents during the afternoon period were analyzed and the summary of results shown in Table 3. The findings indicated that larger proportion of respondents utilized the adaptive opportunities available to them.

From this analysis it can be deduced that the respondents took adaptive actions in the discomfort of the period considered Table 3. Analysis of the resident‟s adaptive actions Adaptive action Drawing the curtains Opening the window Putting on the fan Movement to verandah,balcony,porch Opening the door Sitting closer to window or fan Removal of clothing item Using a hand-fan Taking a cold drink Movement to outside building Movement to different position in room Adjustment of posture Movement to another room Taking a bath Total

Number of residents utilizing action 411 371 352 280 279 251 227 187 174 151 143 121 85 10 3042*

Percentage of residents utilizing action 77.8 70.3 67.7 53.0 52.8 47.5 43.0 35.4 33.0 28.6 27.1 22.9 16.1 1.9

Proportion of use of Adaptive action as percentage 13.51 12.20 11.57 9.20 9.17 8.25 7.46 6.15 5.72 4.96 4.70 3.98 2.80 0.33 100

Note: *More than the number of respondents surveyed as a result of respondents‟ utilization of more than one adaptive action.

According to the adaptive principle. There were 14 adaptive actions taken by residents recorded in the study. The adaptive action that was utilized most by respondents was drawing the curtain with a 13.51% proportion of use. Next to this was opening the window accounting for 12.20% of the different actions. Putting on the fan represented 11.57% proportion of use. The other significantly utilized adaptive actions were the following: movement to verandah, porch, courtyard or balcony, opening the door, sitting closer to window or fan, removal of clothing item, using a hand-fan and taking a cold drink representing 9.20%, 9.17%, 8.25%, 7.46%, 6.15% and 5.72% of the actions respectively. The other less utilized actions were the following: movement to outside of the building, movement to different position in room, adjustment of posture, movement to another room and taking a bath accounting for 4.96%, 4.70%, 3.98%, 2.8% and 0.33% of use respectively. It should be noted that respondents utilized more than one adaptive actions due to their need for thermal comfort and the availability of the adaptive opportunity. The use of drawing the curtain, opening the window and putting on fan were related to the indoor spatial configuration and were foremost in use by respondents. In terms of movement actions of respondents, movement to the verandah, porch or courtyard was utilized most by respondents. This inferred that the verandah, porch and courtyard offered better alternative of comfort to the respondents compared to other spaces and the outside.

The adaptive behavior of building occupants takes two basics form. These are adjustment by changes in clothing, activity, posture and so on to make the occupant comfortable in prevailing conditions and an adjustment of indoor conditions by the use of controls such as windows, blinds, fans and the occupant may also migrate to find improved conditions. It can be seen in the results that the respondents utilized both forms of adaptive behavior. The second option of use of controls and migration was however more utilized than the personal adjustment option. This is a pointer to the need for adaptive opportunity in buildings to enhance this second option. It was inferred that respondents would consider changing something in relation to the building space first before trying an adaptive action with a personal application in order to reduce discomfort.

Respondents may also find it easier to direct their children to effect the desired changes.

The respondents were also asked about their level of preference for each of the adaptive actions considered in this study. The results indicated that higher percentages voted for “very preferable” and “preferable” in each case. Respondents voted notably higher levels of preference for seven adaptive actions in the following order: 1. Putting on fan (60.4% very preferable, 33.9% preferable), 2. Taking a cold drink (49.6% very preferable, 44.3% preferable), 3. Opening the window (48.3% very preferable, 45.5% preferable), 4. Sitting closer to window or fan (42.8% very preferably, 45.3% preferable), 5. Movement to verandah, (39.6% very preferable, 49.2% preferable),

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6. Removing item of clothing (38.1% very preferable, 48.9% preferable), and 7. Drawing of curtain (35.6% very preferable, 49.6% preferable).

This ranking of level of preference gave an indication of the ranking of the cooling effect derived from the adaptive actions or their effectiveness as considered by the respondents.

Analysis of Impact of Adaptive Actions It was needful to determine with statistical tool if there was any effect of the use of adaptive actions on the indoor thermal comfort response of the residents. To determine the impact of the adaptive actions, the Spearman correlation analysis was applied on the thermal response and adaptive actions of respondents. It was found that adaptive thermal response had highly significant correlation with the following adaptive actions: opening the door (r = -0.127 at p=0.003), putting on fan (r = 0.191 at p=0.000), movement to verandah/porch/courtyard (r = -0.161 at p=0.000), using hand fan (r = -0.285 at p= 0.000) and taking a bath (r = 0.092 at p=0.034). The Chi-square test established the relationships between adaptive thermal response and some adaptive actions. In Table 4 are indicated the variables confirmed as having relationship with adaptive thermal response. They were the following: opening the window, opening the door, putting on the fan, using a hand-fan, sitting closer to window or fan, removal of clothing item, taking a cold drink and adjustment of posture.

Table 4. Chi-square result testing relationship of adaptive actions to adaptive thermal response Adaptive action variables Opening the window Drawing the curtains Opening the door Putting on the fan Sitting closer to window or fan Movement to different position in room Movement to verandah, balcony, porch Movement to another room Movement to outside building Removal of clothing item Using a hand-fan Taking a cold drink Adjustment of posture Taking a bath

Chi Square Value 49.408 19.980 43.199 52.533 46.928 14.686 26.032 11.112 7.633 39.977 69.723 34.837 34.640 35.166

df 18 12 12 12 24 18 18 18 12 18 18 18 18 30

Significance 0.000 0.067 0.000 0.000 0.003 0.683 0.099 0.890 0.813 0.005 0.000 0.010 0.010 0.237

Value from table 28.87 21.03 21.03 21.03 36.42 28.87 28.87 28.87 21.03 28.87 28.87 28.87 28.87 43.77

The Adaptive Opportunity in Design Features The adaptive opportunity created in the design features of the buildings was analyzed. Some of the design features and building characteristics examined were found to be correlated to adaptive actions (Table 5).

The physical characteristics of the buildings are: typology, plan and form, house type, number of crossventilated spaces, number of semi- outdoor spaces, proximity to green area and fenestration. It was therefore Table 5. Significant correlation between adaptive actions and building features Adaptive Action

Building Typology

Plan and Form

Opening of window Drawing the curtain Opening the door Putting on fan Move-ment to verandah

r =0.086 p=0.048 r =0.106 p=0.015 r=-0.168 p=0.020 r=-0.168 p=0.000 r =0.153 p=0.000

r =0.086 p=0.048 r=-0.102 p=0.019

r=-0.095 p=0.028

House Type

r=-0.141 p=0.001 r=-0.169 p=0.000 r =0.124 p=0.004

Number of Spaces Crossventi-lated

r= 0.101 p=0.020 r=-0.171 p=0.000 r =0.129 p=0.003

Number of Semi-outdoor Spaces

r =0.157 p=0.000

r =0.187 p=0.000

Proximity to Green area

Fenestration

r=-0.119 p=0.006 r=-0.154 p=0.000 r=-0.147 p=0.001 r =0.145 p=0.001

Inferred that these design features provided the adaptive opportunity for residents to exercise some of the adaptive actions relating to the building. The adaptive actions that related to the physical and spatial characteristics of the buildings are opening of windows, drawing the curtain, opening the door, putting on fan, movement within a space and from space to space as well as movement to semi-outdoor space or outdoor space.

It was found that the following adaptive actions had significant correlation (p < 0.05) with some design features, building characteristics and design typology (all regarded as relevant adaptive opportunity): 1. opening the window had correlation with typology, plan and form; 2. drawing of curtains had correlation with typology, plan and form and proximity to green areas; 3. opening the door had correlation with house type, Typology,

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fenestration, number of spaces cross-ventilated, number of semi-outdoor spaces and proximity to green areas; 4. putting on fan had correlation with house type, typology, plan and form, fenestration, number of spaces crossventilated; 5. movement to verandah/porch/courtyard had correlation with house type, typology, fenestration, number of cross-ventilated spaces, number of semi-outdoor spaces.

The analysis result showed the impact of design features, house type and typology on the adaptive actions taken by the respondents. What this means is that it is in the peculiarity of the physical and spatial components of the building features that adaptive opportunity is generated for the residents. The practical implication of this is that design characteristics of a building play great roles in indoor comfort provision by serving as adaptive opportunities. Proper cross-ventilation of room spaces, provision of semi-outdoor spaces like verandah, courtyard, porch and balcony, adequate and effective fenestration and introduction of trees and landscaping elements are some of the features that were shown to serve as adaptive opportunity in the buildings.

VI. CONCLUSION It can be established from the findings that the adaptive comfort principle was operational within this study context. Some adaptive actions were found correlated with adaptive opportunity as exhibited in the building design features and the design typology. This paper submits that the provision of adaptive opportunity in buildings through appropriate passive design should be exploited to maximize the gains from the adaptive comfort approach. The creation of adaptive opportunity in the design of buildings is recommended as a lowenergy building solution. The utilization of adaptive opportunity in residential building design can find useful application as a passive building design strategy in the warm-humid climatic context.

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