Design errors and variations are inherently part of many construction projects and require deliberate effort to combat. The literature reviewed indicates that empirical studies of the cost effect of design-error-induced variations are scarce. This study investigates the causes of variation on building projects, the frequent design errors that lead to variation, the effects of design error on variation cost, and solutions to design-error-induced variation in design documents. A mixed methods research (interviews and 30 case study building projects) was used to collect the necessary data for the study. Interviews were conducted with 25 construction professionals to obtain information on the causes of variation on building projects and solutions to design-error-induced variation on building construction projects. Thirty documents including valuation breakdowns and variation/change order documents were obtained by convenience sampling technique and used for the extraction of design errors leading to variations and their associated costs. The data was analysed with frequencies and percentages. The study found that poor working drawing and lack of coordination among design documents are the major causes of variation. Errors in design calculations and wrong descriptions in specifications are prominent design errors that led to variation. Design errors account for roughly 36% of the variation cost of building projects. Structural and architectural drawings contain the largest number of errors among design documents, but electrical and mechanical documents have the highest contribution to variation cost. The study concluded that variation costs could be minimized if government policies, aimed at ensuring proper contract documentation, were put in place, and construction professionals were limited to their core roles on construction projects. Rechecking of design documents prior to use, knowledge sharing, and use of computer programs were among the recommended solutions to design-error-induced variation in project documents. Keywords: Construction projects, cost of error, design documents, design error, variation cost, valuation documents

中文翻译：

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对尼日利亚某些建筑项目的设计误差引起的原因，成本影响和解决方案进行评估

设计错误和变更本质上是许多建设项目的一部分，需要进行认真的努力来应对。回顾的文献表明，关于设计错误引起的变化的成本效应的实证研究很少。这项研究调查了建筑项目中的变化原因，导致变化的频繁设计错误，设计错误对变化成本的影响以及设计文档中由设计错误引起的变化的解决方案。混合方法研究（访谈和30个案例研究建筑项目）用于收集研究所需的数据。与25名建筑专业人士进行了访谈，以获取有关建筑项目变化原因的信息以及解决设计错误导致的建筑项目变化的信息。通过便利抽样技术获得了包括估价细目和变更/变更单文件在内的30个文档，并将其用于提取导致变更及其相关成本的设计错误。用频率和百分比分析数据。研究发现，不良的工程图和设计文档之间缺乏协调是造成变化的主要原因。设计计算中的错误和规范中的错误描述是导致变化的突出设计错误。设计错误约占建筑项目变更成本的36％。在设计文件中，结构图和建筑图包含的错误数量最多，而电气和机械文件对变更成本的贡献最大。该研究得出的结论是，如果制定旨在确保适当合同文件的政府政策，并且建筑专业人员仅限于其在建筑项目中的核心角色，则可以将变更成本降至最低。在设计错误引起的项目文档变化的推荐解决方案中，包括在使用前重新检查设计文档，知识共享和计算机程序的使用。关键字：建设项目，错误成本，设计文件，设计错误，变更成本，评估文件 推荐的解决方案包括解决计算机设计错误引起的项目文档变化以及使用计算机程序。关键字：建设项目，错误成本，设计文件，设计错误，变更成本，评估文件 推荐的解决方案包括解决计算机设计错误引起的项目文档变化以及使用计算机程序。关键字：建设项目，错误成本，设计文件，设计错误，变更成本，评估文件