## 6 Technical and Economic Feasibility  
The use of straw as a building material is quite widespread throughout the world. A high concentration of straw buildings can usually be observed where there is intensive cultivation of wheat, barley, and rice. The use of straw material in construction is usually regulated in these countries [15]. It is not easy to obtain reliable information on the precise distribution of straw buildings around the world. The data obtained from censuses, which are drawn up on a voluntary basis, and from private data collections are not uniform. For example, over 5000 straw bale buildings were estimated to exist in France in 2019, with an increase of around 500 new houses per year. However, according to a census, there were only 564 [23]. According to census data, the United States has the largest number of straw bale buildings, with a total of 784 buildings [15]. This technology is used in Italy, mainly in the northern regions of Lombardy, Piedmont, Veneto, Emilia Romagna, and Tuscany, with the number of straw buildings ranging from 176 to 365, depending on the literature source. However, this number has been growing rapidly over the last decade [24] and straw buildings have shown very good energy performances during both the heating and cooling seasons [15; 21; 22]. As a result of their low energy consumption, straw buildings have low operating costs. Casa Cembo, with its wood stove, solar collectors, and photovoltaic modules, but without any mechanical ventilation system, has proved to be a nearly-zero-energy building, with an energy performance index of EP\({}_{\text{H,nd}}\) = 23.4 kWh/m\({}^{2}\)/y. The annual consumption of wood for space heating amounts to 1200-1300 kg, which corresponds to a cost of \(\upxi\)100-150. Comparing Figures 5 and 10, it can be seen that a greenhouse has been installed on the south facade, and therefore it is likely that heating consumption may still decrease. A phase of the study conducted on Casa Cembo concerns an analysis of the building's behavior in summer. On the basis of the technical data reported in Table 4 and the experience of the occupants, it is possible to affirm that (with good bioclimatic design) thermal comfort can be achieved without the use of air conditioning systems. This aspect allows the increase in energy-use trends for space cooling to be reversed [25]. Straw buildings offer two other very important advantages: lower costs and shorter construction times. In Northern Italy, the price of constructing a straw building is about 1200 \(\upxi\)/m\({}^{2}\), which is lower than that of a standard building, which is about 1500 \(\upxi\)/m\({}^{2}\). This difference, which is not large, is linked to the lower cost of materials and to the high cost of labor related to specialized construction. However, the nature of the materials used is fundamental for self-construction, an option that could be adopted by clients to reduce labor costs. Another important advantage that should not be underestimated is related to the possibility of reducing construction times, thus of saving money. Straw structures can be pre-assembled on wooden beams with modular elements. The pre-assembled prototype in Verres (AO) was built with basic modules for the walls, other types of modules that allowed windows and doors of various sizes to be inserted, and other modules again for the floor and the roof. These straw modules are made in sheds and then assembled on site very quickly. Careful planning and qualified personnel are naturally very important for this kind of work. A single-family detached house can generally be built in 4-5 months. However, the pre-assembled prototype for the \"Maison et Loisir\" at the Aosta fair (Italy) was built in only one day and the building was completed on the second day. Electrical and hydraulic systems can be installed in a shed, lowering the overall costs. The Verres prototype cost around \(\upxi\)20,000, corresponding to 1000 \(\upxi\)/m\({}^{2}\).