**1. Introduction**

Nowadays, climate change has become one of the major concerns of all governments and politicians around the world [1, 2]. According to the IPCC, it is expected a temperature increase ranging from 2 to 3.5°C depending on the region [3, 4]. The results proved by some experts in this field showed that sub-Saharan Africa was one of the most vulnerable regions [5, 6]. The objectives of the European Union oriented towards the energy efficiency stipulate that the design of the ecological buildings and more adapted to the new current climate can be a solution to this plague [7]. The search for carbon neutrality by trying to live in the most ecological way is a good thing, but living, in addition, in "green" buildings is even better [8]. The notion of sustainable building varies according to the scientific and specialist fields. Overall, it is a healthy construction, using natural materials [7]. A building must first of all adapt to the man, the well-being of the occupants being capital [9]. Specialists in this field condemn the use of toxic substances in the industrial manufacture of building materials. The key role of energy conservation specialists

is to limit the negative impacts of human habitat on the environment, using state-of-the-art technologies, and to reduce the energy consumption of buildings, houses and buildings [10]. Indeed, they advocate reinforced thermal insulation and sharp construction techniques. "Eco-Builders" consider the building throughout its life. In addition to saving energy, they are also concerned about the origin of the materials used and their management (disposal, recovery) at the end of their life. Sustainable construction is not a specific construction method, but it brings together a set of techniques, materials and technologies that, properly integrated into a building, contributes to enhancing its environmental performance [11]. In its ideal embodiment, green building optimizes energy efficiency, limits water consumption, makes maximum use of recycled, recyclable and non-toxic materials and generates the least amount of waste possible during construction as well as occupation [12]. Around 40% of total energy use and around 24% of CO2 emissions come from worldwide energy use in buildings. Energy use and emissions include both direct, on-site use of fossil fuels as well as indirect use from electricity, district heating/cooling systems and embodied energy in construction materials [13]. The term ZEB is commonly used as propaganda without any mastery of the different realities and constraints specific to each country. There are several methods and strategies to reach net-zero energy, however, for NetZEBs to become mainstream in the international market, it requires several consensus on clear definitions, and also agreement on the building performance which could inform "zero energy" building policy, programs and industry building practices, as well as design tools, case studies and demonstration projects that would support industry adoption [14]. The different objectives of Net zero energy were considered to be a new proposal that was inaccessible because of its high cost, they were recommended only for large projects. Today, it is now possible for all types of construction [15]. Net Zero-Energy Building has become a popular catch phrase to describe the synergy between energy-efficient building and renewable energy utilization to achieve a balanced energy budget over an annual cycle. Several experts have proposed different methods for designing zero energy and carbon buildings in several types of climate [16–22]. But no study has yet been done in the specific case of a country in the Indian Ocean (Madagascar, Mayotte, Reunion, Comoros etc.). This study has for fundamental objective to propose a model of implementation of buildings to Net Zero energy in Madagascar. Section 2 gives the different stages of implementation of this district.
