"Sustainable Development" that was suggested at UN Conference on Environment(1992) held in Brazil led to a rise on importance of environment in various industrial sectors. Especially, a construction part is a field that builds an artificial environmen...
"Sustainable Development" that was suggested at UN Conference on Environment(1992) held in Brazil led to a rise on importance of environment in various industrial sectors. Especially, a construction part is a field that builds an artificial environment for actual life which actively participates in measures to reduce environmental pollutions and save the energy. With the advanced countries leading the way to minimize the energy and environmental impact generated due to use and construction of buildings, various types of "Eco-Friendly Building Certification System" are established and enforced.
The eco-friendly buildings may result in tangible and intangible effects such as the incentive of relevant projects and promotion of housing sales other than just the environmental aspect. However, the buildings with eco-friendly building certification require an additional construction cost owing to the eco-friendly facility and certification standard. An objective evaluation to apply the existing project feasibility evaluation model on the current eco-friendly buildings is difficult since it lacks the additional cost of eco-friendly element.
Thus, the item on eco-friendly cost required for eco-friendly building certification is drawn out in the study. It is applied in the cases to suggest a formula to calculate the additional construction cost for each part due to eco-friendly construction and calculated the additional construction cost for each part based on the formula. To do so, the characteristics of domestic and overseas eco-friendly building certification systems were examined through a theoretical study, and compared and analyzed the certification items. In addition, the concept and analysis procedure of project feasibility were examined.
As the main subject, the additional construction cost item based mainly on eco-friendly building certification standard and construction cost details of cases was drawn out. Also, the formula for additional construction cost of each part was proposed and the amount for each additional construction cost was calculated based on it. Then, the additional construction costs of the calculated cases and the ratio of additional cost per total construction cost for each part were analyzed to analyze the features and factors of construction cost for each part. Moreover, an average additional construction cost per unit area(m²) for each case was calculated to get the average cost of eco-friendly buildings with 'excellent' class and deducted the important factors that influence the additional construction cost.
The study was ordered by S public corporation, implemented based on 5 multi residential housing projects in Seoul that acquired the 'excellent' class for eco-friendly building certification in 2008 and the main study results are as follow.
(1) Based on the eco-friendly building certification standard, the additional construction cost items are drawn out as follow. 6 parts out of 9 parts and total of 14 construction cost items were generated. Currently, the calculation of land use part is analyzed to be impossible since the limitation of standard application scope is indefinite.
(2) The additional cost items for traffic part were an installation cost for bicycle parking place and an installation cost for high-speed information and communication facility. A plan to reduce carbon dioxide which is the environmental pollution part is applied to district unit plan areas and housing development areas, and whether there are cogeneration and district heating established by an upper-level plan determines the above plan so it is excluded from the additional construction cost calculation.
(3) The formula to calculate the additional construction cost for each part was proposed and the amount for each additional construction cost item was calculated based on it.
(4) The additional construction costs of the calculated cases were analyzed. The total construction cost for each case ranges from 824.3 million won to 3,295.5 million won. To obtain an 'excellent' class for eco-friendly building certification, 5.32% of total average construction cost was generated as the additional cost. Average of 2.8%, 1.18% and 0.56% additional cost was generated for indoor environment part, water resource part and energy part respectively. 0.08% of additional cost was generated for traffic part which was the lowest.
(5) The average additional construction cost per unit size(m²) for each case was analyzed to be 40,530 won. Because of selective application of certification item for each case, the construction cost was different. The higher the total floor area of the case, the lower the additional construction cost per unit size. This is generated due to the difference in price and quantity of eco-friendly materials and it is determined that the quantity largely affects the difference in additional construction cost.
The result of this study can be used as a data to build a model on multi residential housing project. This study will be a fundamental study to establish a project feasibility evaluation standard in the future that includes the eco-friendly items through eco-friendly cost items of this study and features of cost for each eco-friendly item.