Energy and environmental assessment of industrial hemp for building applications: a review

Buildings significantly contribute to global environmental pollution due to consumption of both natural and primary-energy resources as well as to emission of carbon dioxide in their life-cycles. Therefore, to enable construction of more sustainable buildings, it is important and urgent that new low-environmental impact materials are developed, mainly by reducing the use of non-renewable resources. In this regard, the recent advances in the development of natural fibres represent a significant opportunity to produce improved-materials and energy from renewable resources. For this purpose, assessments of energy and environmental performances are needed to support both the design and the production of the aforementioned materials so as to identify solutions for enhanced contribution to global sustainability. In this context, this study presented a review of the papers published up to February 2015 that have been focussed upon the assessment of the environmental and energy impacts related to the use of hemp-based materials for building applications. The reviewed studies aimed at testing and improving hygro-thermal properties and eco-friendliness of these materials for reduction of both embodied and operational energy, whilst preserving both indoor air quality and comfort. Doing so would enable limiting the use of energy resources and, as a consequence, their impacts to human health and to the environment, so contributing to making buildings healthier and more environmentally sustainable throughout their life-cycles. Based upon the findings of the studies reviewed, these materials have strengths and weaknesses and their use is strictly dependent upon the given structural situation as well as upon specific requirements of thermal, moisture, fire and sound protection. In particular, all studies concluded that the main strength in the use of hemp-based materials comes from the production phase because of the “green” origin of these materials, mainly associated with the carbon sequestration during plantation growth.