Straw Buildings: A Good Compromise between Environmental Sustainability and Energy-Economic Savings

Some straw buildings, which combine eco-sustainability with versatility, low cost, and fast construction times, have recently been built in Northern Italy. In this work, the technologies used to build straw houses are presented, and the characteristics of the raw materials, the straw bales, and the construction techniques are dealt with. Two straw buildings, which have different characteristics and types of application, are analyzed. The first building is a residential, nearly zero-energy building, which was built in Saluggia (Vercelli) in 2012. This house is presently inhabited by a family and is heated with a wood stove. The second building was built in 2014 in Verres (Aosta) and is a pre-assembled demonstration prototype used for teaching purposes. The thermal performance of the straw envelopes was evaluated during the heating season by measuring the thermal conductance of the straw walls through two experimental campaigns. Straw bale walls offer good insulating performance, as well as high thermal inertia, and can be used in green buildings since straw is derived from agricultural waste, does not require an industrial process, and is degradable. Finally, these characteristics of straw can be combined with its low cost. Local economic development in this field may be possible.