Life Cycle Environmental Sustainability and Energy Assessment of Timber Wall Construction: A Comprehensive Overview

Abstract

This article presents a comprehensive overview of the life cycle environmental and energy assessment for all residential and commercial constructions made of timber walls, globally. The study was carried out based on a systematic literature analysis conducted on the Scopus database. A total of 66 research articles were relevant to timber wall design. Among these, the residential construction sector received more attention than the commercial sector, while the low-rise construction (1–2 stories) gained more attention than high-rise construction (>5 stories). Most of these studies were conducted in Canada, Europe, Malaysia, and the USA. In addition, the end-of-life phase received limited attention compared to upstream phases in most of the studies. We compared all environmental and energy-based life cycle impacts that used “m2” as the functional unit; this group represented 21 research articles. Global warming potential was understandably the most studied life cycle environmental impact category followed by acidification, eutrophication, embodied energy, photochemical oxidation, and abiotic depletion. In terms of global warming impact, the external walls of low-rise buildings emit 18 to 702 kg CO2 kg eq./m2, while the internal walls of the same emit 11 kg CO2 kg eq./m2. In turn, the walls of high-rise buildings carry 114.3 to 227.3 kg CO2 kg eq./m2 in terms of global warming impact. The review highlights variations in timber wall designs and the environmental impact of these variations, together with different system boundaries and varying building lifetimes, as covered in various articles. Finally, a few recommendations have been offered at the end of the article for future researchers of this domain.