more , they show the profitability of each project by discounting the cash flows of both MUCB and MUGB . Thus , the analysis is carried on with a matter-of-fact approach in two phases : by selecting the capital structure which satisfy the minimum DSCR , and by studying the cash flows over the life cycle of the buildings . Finally , financial-plan scenarios are developed through a multivariate analysis changing the values of the two independent variables : loan duration and DSCR target . The outputs of each scenario are the following indicators of profitability and bankability measures : debt percentage , average DSCRpost-tax , yearly minimum revenue , NPV , IRR and Payback .
3.1 Case studies in two Life-Labs The two case studies are part of a larger research project ‘ The Making of a Proto-Tropical Passive and Low-Energy House ’ at the University of Kuala Lumpur . It includes the construction of altogether three sustainable demo-houses M1 , M2 , M3 and the conventional one M0 to run comparative experiments and researches about low and zero-energy efficient buildings in a tropical country . For the research presented here , the two buildings mentioned above are selected and described as such : a ) The conventional MUCB M0 is a standard concrete foundation and sand brick building as it is a “ wall family ” undoubtedly still taking the unquestioned lead in the modern tropical built environment . Replacing traditional clay and stilt houses , it uses basically sand bricks , it is equipped with single glazed metal-framed windows and has a zinc or metal deck roof and gypsum board ceiling . Typically for low-cost housing in tropical countries , a thin gypsum board ceiling and no shading system is provided . With high heat transmission rates and no insulation , this kind of building has both a tremendous heat intake and long daily heat retention cycles to digest by the thermal mass of its bricks . Literally speaking , the walls cannot unload the heat intake it has harvested during the daytime before . b ) Conversely to the open air house , the MUGB M1 is an airtight low-energy house with the same dimensions of its standard counterpart . It uses aerated Lightweight Reinforced Concrete ( LRC ) blocks instead of the standard sand bricks which have a high heat transmission ( U-value of 8.0 ). The producer sells the material as a “ Green Product ” and assures high thermal insulation with U-values of only 2.3-2.4 at the comparative thickness of 10cm . This building will later be equipped with GE solar panels that are used as complementary electricity supply , fitted with 5 cm Wood Wool Cement Boards ( WWCB ) shutters and uPVC low E-glazed windows . The ceiling is also made by a 5 cm layer of WWCB assuring further thermal insulation . Unlike the common almost insulated heat tank of conventional buildings , the ventilated roof allows enhancement in terms of thermal performance . The house follows the principle of the fully insulated building : the airtight low-energy house no longer allows gaps that let the passively or actively cooled indoor air escape and fresh hot air enter the building in an uncontrolled manner during the daytime after about 8:30 am . At a later stage , a CO2 alarm will still enable to house to harvest fresh air during the daytime .
3.2 Data collection The data needed and collected for this research are related to two elements : the construction considered as capital expenditures ( CAPEX ) and the operating expenditures ( OPEX ). The capital expenditure ( CAPEX ) has been gathered comparing the official quotations received independently from local suppliers with the real costs the buildings incurred . Since most of the building elements are sponsored or funded by the private sector , the researchers have contacted those suppliers directly in order to come up with gaging the real final cost of both buildings upon completion . Table 2 shows the overall capital expenditure of MUCB and MUGB inclusive of labour .
102 ZEMCH 2015 | International Conference | Bari - Lecce , Italy