Environmental assessment of MHM building system

With the increasing awareness of climate change and the relevance of carbon sequestration, the use of wood material in building is gaining importance as a way to reduce the impact on global warming. Together with the increasing interest of the public opinion in ecological sustainability, this is leading to the development of alternative building systems. In this context wood has a central role and the demand of wooden buildings, especially houses, is growing. As a consequence, more sustainable wood building systems are being developed. In this study a Life Cycle Assessment (LCA) is carried out to determine the environmental impact of the production of a wooden wall building system, the innovative and relatively recent Massive Holz Mauer system. This system is greatly versatile, does not imply the use of glues, reaches high insulating levels, and contain approximately 100 kg of spruce wood at 12% of moisture content. A gate-to-gate approach has been chosen: from the timber-yard in the sawmill until the wall assembling process. The analyzed scenario uses the primary data supplied by a local sawmill and a company set in North Eastern Italy. The scenario doesn’t include the data from forest operations, products distribution, use and end of life because of the impossibility to collect primary data of these phases. The environmental impact is assessed through four impacts categories: two at global scale, Global Warming Potential (GWP) and Ozone Depletion Potential (ODP), and two at local/regional scale, Photochemical Ozone Creation Potential (POCP) and Human Toxicity Potential (HTP). The functional unit of the LCA is 1 m2 of wall system. The study aims at demonstrating the environmental sustainability of a MHM building system wall production compared to a traditional system. The results of this LCA will be compared with those of concrete based traditional wall having the same insulation values. This study could also contribute to increase the awareness of environmental benefits related to the use of renewable materials towards a standardization of the LCA approach.