Application of off - site construction in Sri Lanka

Abstract

The end of World War II brought an increment in the necessity of building construction along with insufficient provision of conventional constructions. The innovative techniques of Offsite Constructions (OSC) was brought into action to cope up with the risen demand as it delivers the products in desired quality and reduced time of construction. In the present global context, the credit goes to OSC for its process of planning, designing, factory fabrication, transporting and making an assemblage of the fabricated components in a rapid and time-saving on-site fixation, with its appreciable benefits of budget feasibility in cost without hampering the quality or strength of the end product against the conventional construction methods. The implementations of these techniques are rarely bought into practice in the Sri Lanka construction sector. With the aim of increasing the adoption of offsite constructions in Sri Lanka this research examines the nature and level of adoption of different off-site construction systems in Sri Lanka, benefits and barriers in implementing off-site construction methods, and identify the challenges faced in the application of off-site construction methods. Through the snowball method of sampling 60 offsite construction professionals were picked as research samples. The research embraced the survey method; data was gathered through a well structured close ended questionnaire. The data was then statistically analyzed implementing percentage, weighted mean rating and standard deviations to obtain the objectives of the study. The research concluded that all the OSC methods (i.e.; volumetric systems, panelized systems, hybrid construction, and sub-assemblies) are equal in offering high satisfaction, and would boost benefit/income through superior quality, less duration, financial benefits generation from early completion, and onsite less safety risks. The implementation of these methods also minimizes the waste leading to a reduction in the project budget. Contractors‟ profit is high in OSC due to low competitors in industry and due to “design and build” type quotation. The study also brought to light that some critical and dominant challenges out of many are still existent in Sri Lankan construction industry, requiring proper attention for minimizing, or alleviating their impact on the OSC application, such as lack of experienced llaboration groups, complicated project planning and coordination, uncertainty of market demand, unpredictable planning decisions, unable to freeze design early on, fragmented nature of the construction industry, lack of awareness of prefabrication by the market and public, owners‟ negative perception, highly respective construction tolerance, transportation restraints and special requirements to unload OSC components, high initial and capital cost, longer capital payback period, resistance to change, lake of guidance and information, lack of technologies and testing institute, and limited suppliers for OSC components. However, the research also brought to a highlight the benefits such as increasing product quality and reducing construction duration, ensuring time certainty and cost certainty, compensating for shortage of skilled workers, increasing sustainability and value are usually offered or ripped through the implementation of the OSC techniques. Many empirical suggestions were offered in this research to alleviate the obstacles and challenges to the implementation of OSC techniques; including removing logistical constraints, incapability for on-site alterations and expanding the design alternatives.