Climate change can no longer be ignored with the constant rise in the average global temperature. In refugee camps, thousands of shelters built within a short time are more prone to contribute to global climate change if sustainability is not considered from the beginning of the camp planning and shelter design phase. To reverse the phenomena, designers are introducing shelter designs that reduce the use of materials with high-carbon content and release smaller amounts of greenhouse gases into the atmosphere. Such design is known to have a small ecological footprint, which can be defined as the metric allowing for the calculation of an individual’s, a community’s, or a country’s yearly consumption of nature’s resources, expressed in equivalent numbers of “planets.” Building materials for shelters need to be selected carefully since a poor choice may adversely affect their surroundings over their lifetime. Their impact on the environment must be considered, from their harvesting to dismantling the building. This chapter examines various building materials, illustrates how to evaluate their sustainability, and discusses conventional and some of the most environmentally responsible materials available. The chapter begins by highlighting the alarming rates of natural resource consumption and their detrimental environmental effects, such as habitat destruction and carbon emissions. It emphasizes the need to manage resource consumption through tools like the ecological footprint to safeguard ecosystems. The chapter explains that building materials must be selected carefully, considering their embodied energy values. It discusses various materials commonly used in refugee shelter construction, including natural timber, bamboo, adobe bricks, clay or burnt bricks, wattle and daub reinforced mud walls, corrugated galvanized iron, plastic sheets, thatching materials, cement, cement blocks, and quarried materials. Each material is assessed in terms of its environmental impact, highlighting the need for responsible sourcing, manufacturing, and disposal practices. Finally, the chapter provides a case study of Shigeru Ban’s innovative Paper Log Houses, which exemplify cost-effective, recyclable, and easy-to-assemble shelters deployed to aid disaster survivors worldwide.