건축물 생애주기를 고려한 업무용 녹색건축물의 경제성 평가

An Economic Evaluation of Green Business Buildings in Consideration of Life-Cycle Costs and Benefits

The government pursues eco-friendly and low energy buildings by green building policy. Although its incentives are put into action as a part of the policy, further effort is required due to its unsatisfactory outcomes. When we consider that economic value applying green building certification is mainly affected by the free market force, the research on consumer's benefits should be done in the first step. Economic value is mainly examined by simulation studies based on Net Present Value(NPV) and Payback Period(PP) calculation. Costs consist of additional fee for green building certification, while benefits consist of floor area ratio (FAR) incentive, rent increase, tax saving such as acquisition tax and property tax, maintenance expense reduction such as energy and water resource savings. The result indicates that the payback period considering all benefits is 8 years, when the building receives excellent rating for G-SEED and the first class for energy efficiency rating system. However the payback period becomes 23 years without FAR incentive, and 26 years without any incentive. It is concluded that with no incentive, it is not possible for all costs to be paid back within 20 years of life expectancy of the building facilities. Among the incentives the FAR incentive is the most significant factor to ensure the economic feasibility of the green business building. Further studies are needed for capitalize th benefits such as productivity improvement, scholastic performance enhancement, better amenity accessibility and health effect.