In the past decade, there has been an increase in the environmental performance assessment in earth construction through the life cycle assessment (LCA) methodology. A Systematic Literature Review verified LCA methodology trends of five earth construction techniques from 2016 to April 2022, resulting in 27 studies. The results have been analyzed through qualitative thematic analysis, considering LCA methodology. Considering embodied carbon (GWP) and embodied energy, transportation and binder content were the main factors that influenced environmental performance. Hence, earth-based constructions exhibit better results in different impact categories than conventional materials. Environmental guidelines and technical features that were presented in the LCA studies are discussed for Adobe, Cob, Rammed Earth (RE), Compressed Earth Block (CEB), and Light Straw Clay (LSC). This study presents environmental benchmarks at the unit, wall, and building scales aiming to encourage LCA methodology applied to earth construction techniques and fostering the discussion of earth construction sustainability.

The circular economy (CE) has become a trend because concern has arisen regarding the end of life of several products and the reduction of CO₂ emissions in many processes. Since the architecture, engineering, and construction (AEC) industry is one of the biggest generators of environmental impacts, there is a need to apply the CE concept to the industry in order to reduce greenhouse gas (GHG) emissions. However, the role of different tools that are used to integrate CE strategies to reduce GHG emissions by the AEC industry is still unknown in the scientific literature. The purpose of this paper is to carry out a systematic literature review on the theme and analyze the following seven tools: (1) life cycle assessment—LCA; (2) building information modeling—BIM; (3) building environmental certifications—BEC; (4) building materials passports—BMP; (5) waste management plan—WMP; (6) augmented reality—AR; and (7) virtual reality—VR. A total of 30 papers were reviewed, and it was observed that, in terms of CE strategies and climate change mitigation, the vast majority can be classified as closing loops and are mainly related to recycling and reuse at the end of life and the use of recycled materials. Considering the building’s stakeholders, constructors, researchers, and designers can be the main users and, consequently, those that most benefit from the use of the evaluated tools. The integration between LCA, BIM, and BMP was also observed. Finally, as one of the main contributions of this research, other types of integration among the analyzed tools are proposed. These proposals seek to improve and update the tools and also address the need to reduce GHG emissions.

Açaí seed ash (ASA) is a waste product from processing the açaí fruit and burning the seeds for cogeneration purposes. The present study evaluated the use of ASA from the Brazilian Amazon as partial Portland cement replacement in self-leveling mortars (SLM) for social-interest buildings. The fresh and hardened state properties of mortars were accessed with 5% and 10% ASA content, and a life cycle assessment was performed to evaluate the greenhouse gas (GHG) emissions. The maximum transport distance to enable ASA as a building material was determined by a sensitivity analysis, and specific carbon-efficiency indicators for SLM were proposed and validated. The results showed that using up to 10% ASA as cement replacement was technically and environmentally feasible since the mechanical performance was maintained and GHG emissions decreased up to 8%. The sensitivity analysis revealed that transport efficiency is crucial for ASA applications far from its production area; therefore, it should be evaluated as a regional building material. The work brings an important contribution to regional sustainable development by assessing the characteristics of a residual material and proposing the reuse of waste, reducing GHG emissions from the cement industry, and stimulating the circular bioeconomy in the Brazilian Amazon region.