Traditional, state-of-the-art and renewable thermal building insulation materials: An overview

[Display omitted] •Intensive review on traditional and state-of-the-art thermal insulator is conducted.•The focus was placed on researches utilized of renewable resources and wastes.•High thermal insulation capacity construction composites were reviewed.•Challenges facing traditional and state-of-art insulators were discussed.•Advantages and disadvantages of different thermal insulators were demonstrated. Energy saving has become a strategic goal in the whole world, that will lead to protect the environment and conserve natural resources. The energy consumption in buildings for heating and cooling is considered as one of the major sources of energy consumption in a lot of countries. Therefore, there is an ongoing search for finding the proper alternatives to preserve energy and minimize energy losses. Subsequently, heat insulators, part of building materials, are steadily getting their importance as a means of saving energy. Although, a lot of insulation materials are used commercially, this part of building construction still faces different difficulties and challenges such as the cost, thermal and mechanical properties, health problems, etc. Current insulation materials used in construction industry are generally polymer based materials such as polystyrene and polyurethane foam. Although these materials have a high performance in thermal insulation, but the environmental impacts in their production processes are significant. Consequently, the researchers find that there is a necessity to develop and come up with insulating materials that possess excellent properties and at the same time, they have less environmental impacts, and are relatively cheap. In this review paper, the researches carried out in the formulation and development of different kinds of thermal insulation in the last decades are presented. The focus was placed on researches utilized of renewable resources and wastes in thermal insulations development. In addition, the light was shed on the composites materials which was developed as a construction material with high thermal insulation capacity.