Factors impeding the offsite production of housing construction in China: an investigation of current practice

The promotion of offsite production is a possible future strategic direction for the construction industry as it provides economic, environmental and social benefits. However, in China, the uptake of offsite production, particularly in the housing sector, is relatively low and few studies have identified and examined the reasons behind this trend. This research gap is addressed and factors that inhibit the wider use of offsite production in China’s housing construction industry are investigated. A questionnaire survey was carried out, examining the views of 110 construction professionals in China including developers, designers, contractors, manufacturers and suppliers. Factor analysis of 21 separate variables was undertaken which extracted six principal factors, namely: ‘constructability implementation’, ‘social climate and attitudes’, ‘architectural performance’, ‘costing’, ‘supply chain’ and ‘preparatory stage’. The findings identify both barriers and challenges to increasing the uptake of offsite production in China. This provides a rare insight about the housing construction industry in China with possible implications for other developing countries that are seeking to identify and overcome barriers to the wider uptake of offsite production.     

Classification of production systems for industrialized building: a production strategy perspective

The purpose is to develop a matrix for classifying production systems for construction with various degrees of industrialization. Previous attempts to classify industrialized production systems for construction focus on dimensions such as the design process, the product technology, or the supply chain structure, but none of them acknowledge the importance of how orders are actually won in the market and that different market segments have different requirements. Using production strategy theory as a base, a matrix is developed linking market requirements, via the product offering, to the design of the production system. The matrix positions typical production systems based on their respective degrees of product standardization and volumes relative to the degree of offsite production. Similar to production systems in manufacturing, production systems for construction also deliver manufacturing outputs at different levels, indicating that the choice of production system will affect the competitiveness of the company. The applicability of the matrix is exemplified through three case illustrations of concepts for industrialized building, and these show that the matrix can be used to analyse the production systems’ relative strengths and weaknesses. The matrix can also be used as a guide when developing new, or adjusting existing, production systems for industrialized building so that they will match market requirements and offer competitiveness.     

Future opportunities for offsite in the UK

Practitioners' views and opinions on the benefits and drawbacks of offsite technologies in the UK construction industry can vary widely, often depending upon their role or position. This research provides an indication of the opinions of the different sectors within the industry, including clients, designers, contractors and offsite suppliers, together with some predictions for the future growth of the offsite sector in the UK. A questionnaire survey of UK construction was conducted in order to target the three main construction industry sectors—suppliers/manufacturers, contractors and designers/clients. More than 80 questionnaires were completed and returned. The vast majority of practitioners within the industry are aware of the possibilities and potential of offsite, and most also understand the advantages and disadvantages of its use. The value of the UK offsite market was valued at £2.2bn in 2004 and the demand for offsite is clearly increasing, but it is not always clear in a project who is the main driver for its use. For the offsite market to develop further however, two main problems need to be addressed; the lack of transparent information for the decision makers in the construction process, particularly that relating to comparative costs, and the lack of available multi‐skilled labour to work in the offsite factories.     

Demystifying the cost barriers to offsite construction in the UK

Offsite construction has long been reported as an effective alternative to conventional construction, with wide-ranging benefits. However, a wider take-up has been inhibited by perceived cost barriers which are insufficiently studied. Such cost barriers are addressed, drawing on an examination of the cost performance of four types of construction method: pre-cast concrete cross-wall panel, in-situ reinforced concrete (RC) frame, steel frame and timber frame. Data were collected for 20 medium to high rise residential buildings of eight projects by a leading UK housebuilder over a five-year period (2004–08). In all cases, detailed cost comparisons were completed for build method selection. Cross-wall was found to be consistently cheaper than RC frame or steel frame by 11% to 32% in the projects. The process of developing and innovating cross-wall technology led to sustained cost savings up to 25% from its first use. Cross-wall construction also improved cost effectiveness of 20-storey high rise buildings over other solutions. Cost engineering means for achieving cost reduction and effectiveness are identified, which included efficiency learning, technological innovation, multinational partnering, and ‘in-house’ build management. The results prove the logic of the experience curve in improving the cost efficiency of offsite construction, and should encourage offsite construction in the future.     

Assessment of construction defects in residential buildings in Spain

The building industry is noted for its repeated building defects causing cost increases and time delays during construction. In Spain, despite the Ley de Ordenación de la Edificación (Building Regulation Act), which establishes a general framework to promote overall building quality, construction defects in residential buildings remain a pervasive problem. An analysis of 3647 construction defects is presented which identified the location within the building, subcontractors and building element in 68 residential building developments undertaken by two large Spanish contractors. The research reveals that the most common defects that arise during construction are related to the stability of the structure and inappropriate installation of roofs and facades. These technical faults are caused by poor workmanship rather than by the quality of the materials or products used. By comparing these results with a previous study on defects after handover, it can be concluded that while the nature of defects during construction is basically technical, at handover it is aesthetic or technical.     

Handover defects: comparison of construction and post-handover housing defects

Although inspections occur during construction or at handover, customers do not normally participate. This situation creates a gap between the quality perceived by both contractors and customers. An analysis of 52 552 handover defects in 2179 flats in Spain is presented which identified their nature, the building element and trade where these defects are located. These results are compared with previous studies that analysed defects detected during the construction stage and those that remain after handing over the building to the client. The research reveals that structural defects are resolved during construction due to existing quality standards. However, other aesthetic and functional defects remain and/or arise at handover. Some defects are not resolved until customers complain after they first occupy the dwelling. Many functional defects arise due to the lack of involvement of end users in the early project stages.     

装配整体式住宅建造过程质量缺陷研究

为了解装配式建筑质量缺陷,通过分析济南某装配整体式高层住宅项目的现场文档资料,梳理出23个方面质量缺陷,66种缺陷表现形式,运用排列图法从设计、生产及运输、施工3个环节对质量缺陷进行定量统计,确定每个环节主要质量缺陷,解释缺陷产生原因并提出缺陷防治建议。结果表明,装配式建筑对设计工作提出了更高要求,做好构件深化设计工作对减少缺陷具有决定性作用。对生产及运输环节和施工环节质量缺陷防治,要从技术改进和强化管理措施两方面入手。出现频数高且发生在整个过程的缺陷考虑从技术层面解决,频数较低且时间分布离散性大的加强现场质量管控。3个环节主要质量缺陷、表现形式、产生原因及防治建议可为此类工程进行质量管理提供参考借鉴。     

房屋建筑工程施工质量管理

根据自己的工作实际,从提高质量的角度探讨了如何在房屋建筑工程施工的各个环节加强质量管理工作,并提出了相应的管理措施,以期确保工程质量,提高社会和经济效益。     

建设工程质量问题监督处置方法研究

建设工程质量问题按其属性可分为质量行为问题和工程实体质量问题,按其危害后果严重程度,可分为一般、严重和特别严重三个等级。对于一般质量问题,监督员可只核查质量问题整改合格证明资料即可,而对于严重或特别严重质量问题,监督员应到施工现场核查质量问题是否整改合格。同时,对于特别严重质量问题,还应予以行政处罚。对不同等级的质量问题,采取不同的处置方法,既让监督员抓住重要质量问题,提高工作效率,又能坚守任何质量问题都不放过的职业道德底线。     

全装修住宅质量通病及其思考

通过对全装修住宅质量通病形成原因全面分析,结合实际工程,提出了全装修住宅质量通病的治理要在设计、施工、验收等建设的全过程加强管理、予以防治.     

CME Forum: a response to “Construction flow index: a metric of production flow quality in construction”

The study of types of flow in construction is a relatively new field. This paper reviews the work of Sacks et al. and reveals that they have applied a production-line metaphor with recognition of two production flows. Process flow: locations are equated with products moving down a production line. Operations flow: work crews are equated to work stations. Their work proposes an index of the quality of production flow in construction, but the research design has three significant flaws: the skilled interpretation of flow-line charts is not in turn applied to the interpretation of their example charts; the conceptual framework does recognize that the underlying metaphor requires levels of detail in both location and task that is not supported in their analysis. The meaning of “quality of flow” in this context is not defined. This debate raises important epistemological questions for those working in lean construction and location-based management. While the concept of “production flow quality” is important, the Sacks et al. methodology does not address the detailed planning of individual crews. It is only possible to apply the production-line metaphor if micro-management is adopted as detailed planning.     

Towards adoption of prefabrication in construction

There is an urgent issue on huge quantities of wastage generation in construction. There should not be lack of environmental support from construction stakeholders. The current implementation of prefabrication seems unable to provide satisfactory results to the construction industry. This paper provides a feasibility analysis in adopting prefabrication in construction activities. Advantages, hindrances and future development on prefabrication's applications are provided based on a questionnaire survey. The suitability in adopting prefabrication of various project types is also examined. Furthermore, a financial analysis is also investigated by a local case study. It found that wastage generation can reduce up to 100% after adopting prefabrication, in which up to 84.7% can be saved on wastage reduction.     

公共租赁住房标准化设计与部品化建造的技术研究——北京公共租赁住房示范工程·众美光合原著项目的建设实践

本文分析了我国公共租赁住房建设问题和发展趋势,提出了量产化背景下基于公共租赁住房工业化生产建造方式、公共租赁住房标准化设计与部品化建造相结合的可持续建设理念,阐述了公共租赁住房标准化设计与部品化建造的整体解决方案,并对北京公共租赁住房示范工程“众美光合原著”项目的工业化集成技术应用进行了深入讨论。     

预拌混凝土的施工质量控制与管理

基于当前预拌混凝土的性能优势和质量缺陷,分析了影响预拌混凝土质量的因素,从混凝土拌合物性能和施工控制与管理等主要方面研究了相关的质量控制技术方法.     

零缺陷质量管理在桥梁施工中的应用控制

提出了“零缺陷”管理的新概念、新思维,论述了“零缺陷”质量管理在施工过程中的控制情况,通过“零缺陷”管理在桥梁施工中各个环节的具体应用实例,进一步阐明了“零缺陷”管理方法,以使零缺陷质量管理真正服务于工程建设。     

经济适用房建设问题的研究

根据目前实际情况,通过对经济适用房的分析,提出了一些建设性意见,以求解决经济适用房建设中存在的问题,完善经济适用房制度,对促进房地产健康发展发挥了巨大作用。     

钻孔桩施工中的问题处理

通过对铁路、公路、房建等项目的施工中出现的钻孔桩事故的分析、总结，介绍了一些在钻孔桩施工中出现的工程事故和质量缺陷，并提出了处理思路及方法。     

房建工程项目管理问题的具体表现与对策

房屋建筑工程对于工程项目的专业化操作与管理的要求比较高,但现阶段我国房屋建筑工程的项目管理还存在着很多问题。基于此,本文主要从概念、内容和特点三个方面对房建工程的项目管理进行了简单的分析与探讨。