Comparative Study of Cost Estimate System in Landscape Architectural Construction - Comparison of Unit Price between Actual Construction Cost and Standard Quantity per Unit -

This study aims to find a proper construction cost calculation method by comparing unit prices of cost estimate in landscape construction among other public ordering construction projects. There were 7 out of 12 items from the actual work cost in the first half of 2011 were compared. The 12 items were classified as landscape Architectural construction and the 7 items were the approximate standard. As applied construction types, the comparable 35 items out of the 80 actual work cost items applied to 5 sites were compared to the unit price of the standard quantity per unit in March 2011, which was the approximate standard. Actual construction rate of the 7 items in the category of landscape sector was 104.86% for each item and 92.09% as a total construction cost. The high actual construction rate was caused by the high rate of seed spray depending on the status of applying rocks. However, there were more fundamental reasons for the cost generated from aslope treatment for grass and seed spray. So, it requires more detailed regulations on the modification factors for each soil type, the standard and needs to improve theillogical standard quantity per unit system. Actual construction rate of the 35 items in the applied sectors of civil engineering and architecture was 78.65% for each item and 71.31% (70.17%) as a total construction cost. This shows that actual unit cost cannot reflect actual cost structurally and standard quantity per unit system lacks practicality in terms of construction due to thelabor force. 85.1~91.2 % actual construction rate announced by the Ministry of Land and Maritime Affairs referred to the newly switched items. So the result was estimated as actual construction rate. This requires supplementation after verification in order to make the actual work cost produce at a proper rate. Also, standard quantity per unit system needs complementation with these actual data and so on.

조경공사 적산방식의 비교연구 - 실적공사비와 표준품셈의 단가비교 -

본 연구는 공공건설공사 중 조경공사 적산의 단가 비교로 적정 공사비 산출방안을 모색하고자 하였다. 2011년 상반기 실적단가에서 조경공사로 분류되는 12항목 중 유사기준인 7항목을 대비하며, 준용 공종은 5개 현장에 적용된 실적단가 80항목 중 비교 가능한 35항목을 유사기준인 2011년 3월의 표준품셈 단가로 대비하였다. 조경부문 7항목의 실적공사비율은 항목별로는 104.86%, 총공사비로는 92.09%이다. 실적공사비율이 높은 이유는 암반 적용 여부로 씨앗뿜어붙이기의 높은 비율도 있지만, 근본적인 이유는 잔디와 씨앗뿜어붙이기의 사면처리 비용 때문이므로, 품셈의 불합리성과 토양 종류별 기준별 보정계수 규정을 세분할 필요가 있다. 토목과 건축 준용부문 35항목의 실적공사비율은 항목별로 78.65%, 총공사비로는 71.31%(70.17%)이다. 이는 실적단가가 구조적으로 실제 금액을 반영하지 못하는 점과, 품셈은 인력시공에서 현실성이 결여된 때문으로 판단된다. 국토해양부 발표인 85.1~91.2%의 실적공사비율은 신규 전환품목 단가이므로, 이 결과는 실제적인 실적공사비율로 추정되며, 실적단가가 적정 비율을 보이도록 검증 후 보완하고 표준품셈도 이러한 실적자료 등으로 보완이 필요하다.