透天建築工程數量計算之案例探討

Abstract

營建承攬工程契約之規劃、基本設計等初步階段裡，工程數量在建築估價中為不易變動之部分。其相關工程材料大多由建築師事務所或建築公司做初步之估算，或是將設計好之圖說交給估算公司計算，最後營造廠在投標時做詳細計算以便投標。然而數量計算結果與實際數量誤差不能相差太遠，否則會影響投標估價之決定。因此為了降低工程數量計算結果之誤差，一般工程業界皆有自己的一套計算原則供計算參考以便於工程數量計算之進行。本研究針對透天建築工程部分，透過與工程顧問公司、建築事務所、估算公司以及營造公司等業界專家訪談方式，蒐集其對於工程數量計算原則之見解，並將訪談後之計算原則彙整，藉此過濾計算繁雜步驟以及避免誤算導致漏項漏列或重複計算，並利用訪談後之原則去計算透天建築工程數量各個項目。本研究以一個透天建築工程為例，根據訪談過後建築估價所需之工程數量計算原則得出其計算結果，便於往後學術工程計算上使用。本研究最主要探討之部分為各工程之計算原則，包含假設工程、土方工程、結構體工程、裝修工程等等，其中又以結構體工程(包含鋼筋、模板、混凝土)之計算原則最為重要，而業界計算參考之原則不盡相同，因此藉由業界訪談方式將各家計算原則蒐集並彙整，希望能將計算原則統一標準化可供參考，有利於往後工程投標估價之進行。

The quantity of construction projects is an invariable component for the valuation of the construction cost in planning the construction contract and the preliminary basic design. Architect office or construction company estimate the preliminary cost of construction materials or invite a survey firm to figure out the cost of project based on the design drawing. Finally construction companies work out the cost in detail for bidding. The estimate must be close to the actual cost so that it will not affect the bidding. To reduce errors, in the engineering industry, there are standard principles for the calculation of construction projects. This study will focus on the housing construction project. The data are collected through the interviews with many engineering consultants, architects, engineering estimates companies, as well as construction companies. In this study, we will carefully examine the complicated steps of calculation, avoiding double counting or missing items. We will use the collected principles to calculate each item of the housing construction. We hope the results of one particular housing construction case can be used as an example in academic projects on the calculation. This study will focus on the principles for the cost calculation of construction projects, including temporary work, earthwork, structured construction, renovation and so on. The most important is the calculation principle of structure construction (including rebar, formwork, and concrete). The calculation principles may vary among construction companies and thus various calculation principles are collected through the interviews with construction industry for the purpose of standardizing the calculation principles so as to facilitate the cost estimation for future bidding.