###### Abstract  
In this study, we propose a methodology for constructing a prototype room intended primarily for people with low incomes, allowing self-construction practices and upcycling of widely available waste materials in their original form. Mechanical tests were conducted on single bottles of poly(ethylene terephthalalate) (PET) filled with different materials as well as on entire PET bottle/concrete blocks. Higher strength was observed when the bottles were in a horizontal position. The mechanical performance of the construction solution adopted for the prototype was not tested, and therefore its structural adequacy was not proven. The insulating multilayer roof was composed of waste plastic bags, two layers of uncapped PET bottles of differing shapes and sizes, another layer of plastic bags, waste cardboard, soil from the site, and a top endemic plant green layer. The PET bottles used in construction were filled with clay from the site, although bottles filled with fly ash achieved better mechanical results. The bottles can also be used uncapped and empty, which would simplify the process considerably by reducing the filling stage. This can be considered to be the main proposal for this type of building. There were almost negligible solid wastes generated, since they were used in the multilayered green roof. From a top view, the prototype mimics the surroundings because the green roof incorporates soil from the site and endemic plants. sustainability; recycling; alternative materials; green building; self-construction; thermal conductivity; civil engineering +
Footnote †: journal: Applied Sciences  
**Chair:**  
**1**  
**[PERSON] 3(r), [PERSON] 3(r), [PERSON] 2 and [PERSON] 4**  
Footnote 3: Facultad de Ingeniería, Universidad Autónoma de Quééretaro, Quéératore 76000, Mexico; [EMAIL_ADDRESS] (J.L.R.A. ); [EMAIL_ADDRESS] (R.R.J.) Footnote 4: Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Unidad Quéretaro, Quératore 76230, Mexico; [EMAIL_ADDRESS]  
Footnote 5: Correspondence: [EMAIL_ADDRESS] (J.d.J.P.B. ); [EMAIL_ADDRESS] (M.L.M.L. ); Tel. : +52-442-211-6090 (J.d.J.P.B.) Footnote  
The construction industry has been trying to reduce its negative impacts on the environment [6]. Some techniques, designs, innovative materials, and recycling efforts have been implemented in the construction of sustainable buildings [4; 6]. The study and use of green roofs have been increasing [9; 10; 11; 12; 13; 14], mainly for the benefit of internal thermal comfort [11], but also for improving community welfare by mitigating the urban heat island effect [15; 16; 17]. Green roofs reduce energy consumption and indoor pollution, which is particularly important for low-income people [18]. Today, the construction industry is assuming a retro vogue approach, using locally available building materials such as wood [19; 20; 21; 22], cane [23; 24; 25], stone [26; 27], mud (adobe) [25], jute [28; 29; 30; 31; 32], hemp [28], lime [31; 32], and bamboo [22]. These materials have countless forms in use and have been modernized. Poly(ethylene terephthalate) (PET) is widely used, especially for carbonated beverages, drinking water, juices, etc. [33; 34; 35; 36; 37]. There have been an increasing number of studies on using PET incorporated into concrete and considering cutting bottles and using them as small pieces or fibers [38; 39; 40; 41; 42] rather than using the entire bottle in its original shape. In 2019, according to the National Association for PET Container Resources (NAPCOR), in United States, the recycling rate of PET plastic bottles was 27.9% [43]. Including Canada and Mexico, North America's PET recycling rate was about 35% in 2019. The use of PET bottles is growing around the world, but its recycling is also increasing. As a building material, PET is readily and broadly available for people to use, especially if the construction technique does not require further processing.