Rethinking the Malaysian Affordable Housing Design Typology in View of Global Warming Considerations

With the advent of the global warming and the resulting climate change, many sectors of a country’s socio-economic activities have taken several initiatives to reduce environmental destruction without compromising human physiological and psychological needs. This includes human need for comfortable and affordable homes. Over the years, the design typologies for affordable housing have evolved from a two-bedroom to a compulsory three-bedroom dwelling in order to address the cultural need to separate siblings of different sexes in separate rooms. Build up area from the initial 550 square feet has risen to the now 700 square feet. This article advocates for a more humane design to include the element of environmental comfort to come into play in the design typology for future affordable housing even though some compromises have to be made in terms of price. This paper compares the existing affordable housing design status quo and suggests a new design paradigm in view of the requirements by the Malaysian Green Building Index.


Introduction
With the growing concern of the global warming and climate change, building professionals are advised to look again at the environmental factor in designing buildings in the tropical climates.Many times the same mistake was repeated only to aggravate the already worsening condition of the climate outside the building.Economic progress has been proceeding at an unprecedented pace that created many heat islands in urban areas.Jungles were cleared to make way for economic progress by providing housing estates, factories, commercial areas and institutions.These changes in urban area have been replacing the natural green surroundings with the hard landscaping, which reduce the cooling effects of evapotranspiration, shade as well as the strategy of cooling winds regarding to buildings' density.These issues have affected directly on reducing the reflectivity of urban area and increasing the absorptivity due to the thermal properties of buildings that add heat to the air by conduction.In addition, the burning of fossil fuels to provide electricity for air-conditioning, fans and to operate mechanical and electrical appliances has assisted to generate more heat.By-products of these activities from the energy provided lead to the release of toxic gases such as carbon monoxide from motor vehicles.The release of carbon dioxide to the atmosphere is reaching at an alarming rate that prevented heat to be reflected back to the outer space and thus cause heat to be trapped within the earth's atmosphere.Therefore, these indicators support to create an artificial warming which reflects in the temperature record.Recent studies show that depending on the weather conditions, the overnight temperature in the center of urban areas can reach up to 10°C warmer than rural environment (Climate and water agency, 2002).This is known as the Greenhouse Effect.
According to Gill et al. (2011) evidence proofed that built environment is one of the major contributors of energy needs and carbon emissions (Meeting the Energy Challenge, 2007;Fox, 2009).Residential sector plays a significant role contributing almost 30% of carbon emissions and energy use (King et al., 2008;Utley & Shorrock, 2008).IEA, 2009 statistics showed that more than 20% of the electricity in Malaysia is being used in the residential sector. Figure 1 shows the level of CO 2 emission in Malaysia is increasing critically (IEA, 2009) since 1970 which represents as one of the highest emitters of CO 2 compared to other countries in Southeast Asia.These data show serious indicators of growing in the demand of the energy in the 21st century.2006) mentioned that a young single person will probably expect to rent but a married couple with a child will consider buying a house.

Conventional Present Day Affordable House
The present-day affordable terrace house requires a transformation in line with changes that has been happening worldwide especially in terms of adapting to the global warming, fast pace modern technological advances, for example the ICT and its peripheries and expanding population (Friedman, 2008).Population growth in Malaysia is predicted to be 33.4 million by 2020 (Ministry of National Unity and Social Development, 1999).Md.Sani (2007) identified six factors that influence affordability of the low-income group to own a house, namely, (i) collective income (ii) household expenditure (iii) type of occupation (iv) level of education (v) breadwinners and (vi) amount of house monthly payment.The breakdown of affordability as given by Md.Sani ( 2007) is shown in Table 1.From the above table, the majority 68.6% pay between RM100 to RM200 a month for a house.The proposed design will have to consider this group so that any increase for human comfort would not be a burden in affordability.The low-cost single-storey terraced house typology (Figure 2) is taken as a case study.A maximum of 700 square feet is allowable and therefore, is always constructed to the optimum.A 6.5 meters is a typical frontage width and 11 meters deep.This means that the volume of air mass inside the building will get warmer as the day begins from sunrise to sunset.And to make it worse cement bricks are used as walls and cement roof tiles as roof finishes.The properties of both these materials are that cement based materials readily absorbs and stores heat.At night time when the air is cooler outside the brickwall and roof readily releases the stored heat thus warming the interiors.
A high ceiling interior would take a longer time to warm the air inside, but this is not the case for low-cost design where minimum dimensions rule.Minimum dimensions are acceptable only with the use of building materials that are highly insulated from the sun's heat, but this only raises the building cost.As for the internal activities such as cooking in the kitchen, lights switched on in the middle of the dwelling due to deep plan, TV on, fans to forced circulation of warm air, further contributes to the warm indoor environment.To counter this is to cross ventilate, as the experts say, but when the external air is already warmed up by terrestrial re-radiation due to hard landscaping, equilibrium is reached between the outside and the indoor air temperatures, so no natural cross ventilation is possible.Thus, adapting sustainable development concept design as strategies to terraced houses can improve the indoor thermal comfort and alleviate the need for mechanical cooling.This concept is combining climatology, thermodynamics primarily focusing on heat transfer and human thermal comfort, achieving cooling methods independent of, or infrequently requiring, active systems.To comprehend the environment role more clearly to help in the design, Passive Architecture is a concept designed to be responsive to the local climatic conditions (Zaki et al., 2007).The terminology is conveyed as 'passive' protective approach of house design in shielding occupants from the local climate elements; and 'architecture' place this responsibility to the Architect being the 'Principal Submitting Person' in the Uniform Building By Law and the profession is obligated to create good building design (Zaki et al., 2008).It is also called 'ecological building' and 'green building', which is also well known as 'energy efficient building' and 'healthy building' (Zhu & Lin, 2004).
In addition, Zhu and Lin (2004) stressed that passive technique requires from the designer to consider (i) Orientation; Thomas and Garnham (2007) recommended building orientation is an essential first action in making "passive" building, and it should be determined by factors of the sun and the prevailing winds; (ii) Building Form; Buildings in the tropics requires to limit its exposure on east and west sides, the optimum form is inevitably rectangular (Konya, 1980) Therefore, Malaysia must relook into the present housing design policies and to determine that archaic policies must be obviated, modified and when necessary new ones formulated.Government agencies are still in the dark as to how to go about to improve public housing conditions towards sustainability and time will tell how successful the initiatives would be.A house should be a home and not just a shelter, but existing stock of low-cost houses aims for quantity and compromises on quality.A well designed affordable housing that considers the environment would be conducive to the public health in general and reduce the length of queues at the hospitals.There is now a dire need for an improvement in the living conditions inside the house that would be more conducive to the healthy lifestyle.Wholesome living need not to be expensive but can be affordable if designed for the environment in mind and not just mere production numbers.

Proposed Future Affordable Design
A rethinking in the design of future affordable houses should consider the effects of global warming.A proposed design shown in Figure 3 is a shift in design paradigm for the affordable housing.The build-up area is almost similar to Figure 2 but slightly bigger with a 10-meter wide frontage and 6.7 meters deep, thereby giving a total of about 67 square meters (722.26sq.ft.).There are a lot more opening area for good day-lighting and with only a depth of 6.7 meter, effective cross ventilation is predictable.Painting the roof white would help in reflecting the sun's heat.This has been scientifically proven of its effectiveness as a white body.To further cool the roof space, a hybrid turbine ventilator (HTV) is installed to extract hot air from the attic space.The HTV extracts hot air via 40W solar-powered extractor fan.As long as there is light the HTV will keep on rotating to extract the hot air out until sunset.Without inducement of extraction, the existing turbine ventilator in the market is not effective enough. Figure 4 illustrates how and where the HTV is used (Ismail & Abdul Rahman, 2012).There are many inexpensive options when considering applying the passive design elements.These elements prevent heat absorption.Whitewashing reflects heat, HTV extracts hot air out of the building fabric, and orientation prevents the sun from entering into the interiors.

Daylig
The simul desired day during wak The conve and therefo 12:00 mid recommen    Due to the difference in floor area between the conventional low cost terrace and the new design, the total cost of one intermediate unit does not compare apple to apple.Therefore, the cost per sq ft. will provide a clearer picture of the cost between both designs.Table 3 shows that the cost of proposed design is 0.08% cost higher than the conventional design even though the floor area is comparatively less.This additional cost is due to the extra number of windows and rainwater harvesting installation.However, these additional costs are to be absorbed by the savings from the reduced use of artificial lighting, improved ventilation, water savings from rainwater harvesting and sale of vegetable produce from the small garden that comes together with the design.Overall, there is an addition of RM7.00 per sq.ft. for the proposed design.Nevertheless, this 0.08% increase in cost will create better living conditions that may improve the general health for the occupants.The newly introduced passive design elements, the vegetable gardens and the rainwater harvesting will eventually offset the increase in building cost; (i) Firstly, the reduced indoor air temperature means decreased electricity consumption to cool for thermal comfort.
(ii) Secondly, more windows mean more daylight enters the interior and therefore, less electricity consumption for artificial lighting.
(iii) Thirdly, the vegetable gardens provide the occupant the opportunity to grow their own vegetables for personal consumption or can be grown to be sold at night markets.These gardens add to household income by not buying vegetables or fruits at markets or selling them whereas, add to their household income.
(iv) Fourthly, the rainwater harvesting reduces water consumption for the vegetable garden, for washing compounds or vehicles.Thus, water savings mean savings in water bill.

Conclusion
This paper provides a clear view of the relationship between global warming effects and the affordable housing design and how these issues affect affordability.The results lead to adapted various concepts and strategies to fit the requirements for existing condition.These modifications and alterations help to curb the extensive needs of energy by providing more appropriate built environment for human comfort.This step leads to zoom clearly on the relation between economic and environmental situation in building environment by solving the problem of unprofessional design methods in the construction field.As a result, these findings could help to control the expansion of greenhouse gases in the future while maintaining for optimum and affordable price.Therefore, from observations and literature reviews on affordable housing in the Malaysian market, a few recommendations may aid architects and designers in the coming up with creative typologies while achieving energy efficiency and indoor comfort.Through empirical and simulation studies, it has shown that not only in providing the occupiers the thermal comfort but also psychological comfort as well.The conventional design seemed to be claustrophobic, and this has to be addressed by the proper orientation as shown in Figure 3. Thus, comfort has to be two pronged, thermal and psychological.Indoor wall should be given a lively finish and stimulating visually to enhance the psychological aspect of the human behavior.Pastel light color for internal walls would be the cheapest and also stimulating.Providing a courtyard would give multi-purpose spaces that allow the occupiers the choice of deciding what greens they prefer.And if done consistently that particular row of houses would give a pleasant setting by the variety of plants planted at intervals between the units.It would add color and life to the neighborhood.Occupiers or owners must also be educated on the use of energy in homes and how to minimize energy usage without compromising on living standards.They are also to make some habitual adjustments to accommodate the physics of microclimatic behavior.Understanding the microclimate would be a great advantage because the owner would be able to do inexpensive adjustments to suit their lifestyles and finally there Figure 3. T Fig Figu

Table 1 .
Breakdown of income, expenses & monthly payment Konya (1980))environment or Ventilation; in the hot and humid climate, ventilation requires larger sizes of window openings to catch a breeze from the prevailing wind(Konya, 1980); (iv) Outdoor thermal environment of the dwelling district; (v) Adequate day-lighting should be provided in all living spaces while caution must be taken in tropics; (vi) Noise pollution and sound insulation; (vii) Wall and Roof Insulation;Konya (1980)stressed especially to adequately insulate the roof because the heat gain in the tropical countries is the maximum on top of a building.Koch-Nielson (2007)proposed that air is the best insulator such as pitched roof with raised ridge that causes stack effect; (ix) Passive Cooling; uses design aspects or technologies to stimulate air flow and cool the environment without dependence on energy sources or power consumption.As a result, in hot and humid tropics such as Malaysia, Passive Architecture design approaches target to avoid heat from the sun, stimulate natural cross ventilation from the prevailing wind and ensure daylight into the building.

Table 3 .
Cost Comparison between Conventional and Proposed layout plans for one intermediate unit