As the global economy develops and population increases, substantial fossil energy use has caused a sizable increase in greenhouse gas emission and the subsequent greenhouse effect, leading to global warming. Reducing greenhouse gas emission and forest resource consumption is imperative. Producing, manufacturing, and using construction materials such as concrete, steel, and formworks consume abundant energy and produce considerable waste, affecting the natural environment. Specifically, formwork engineering, which involves substantial forest resource harvesting and waste production in manufacturing and using timber formworks, requires attention. Ctirrently, formwork engineering in Taiwan has typically adopted timber formworks. In 2013-2015, the annual average total floor area of reinforced concrete buildings was 30,950,383 m(2) in Taiwan. Converting this number to the number of timber formworks revealed that a staggering 1,843,437 cedar trees aged 30 years were required annually for the aforementioned total area, excluding other types of engineering such as bridges and retaining walls. This study sought to reduce the use of timber formworks to decrease deforestation, preventing forest resource depletion. Specifically, plastic formworks exhibit considerably improved reusability, low manufacturing costs, and favorable recyclability. The recyclability of plastic formworks enables the reuse of the material and purpose of environmental sustainability. (C) 2017 Elsevier B.V. All rights reserved.