From Earth to Aerogel: Technology Reshaping Construction

In 2023, 13% of greenhouse gas emissions in the United States could be tied to commercial and residential buildings. As the population increases and more buildings are constructed, this percentage threatens to become even higher if American construction firms don’t do anything about it. With our species threatened by climate change, it is important to reduce greenhouse gas emissions and waste, wherever possible. Fortunately, there are many innovative methods builders can use to reduce both the material waste involved in constructing buildings and the energy waste involved in operating them.

One way builders can contribute to sustainability is by using sustainable materials like adobe and rammed earth bricks that are not only easily sourced, but also have impressive thermal properties and are simple to manufacture. Adobe bricks have been used to build structures in what is now the Southwestern United States since the Pueblo people inhabited the area; the brick is capable of absorbing much heat without it entering the interior (it has a specific heat capacity of 1 kJ/(kg K)) and it releases that heat during the night time when it is cold. These properties make it ideal for arid environments, but such an environment is not a necessity: adobe bricks can be produced in an environment in which it does not rain for at least one week, meaning it can be produced locally in many different areas of the world. Further, adobe requires very little energy to manufacture and many different kinds of soil can be used. Similarly, rammed earth has been used all over the world for thousands of years, from the Alhambra in Spain to the Great Wall of China. It’s simple to use, builders simply create a form out of wood for the object they want to create, fill it with dirt, and compress it until it becomes solid enough to work as a building material. The process can be repeated either on the scale of individual bricks or, the more recently common method, for whole wall segments until the wall is at the desired height. Rammed earth is similar to sedimentary rocks, utilizing dirt with a mixture of silt, clay, gravel, and sand. As opposed to adobe bricks, rammed earth requires a humid environment in order to be formed. Both adobe and rammed earth utilize locally-sourced materials, result in minimal waste, require little energy to create, and have good thermal insulation properties.

Once a building has been created, it must be properly air conditioned and heated to provide comfort to the people inside. Although doing this takes a lot of energy overall, there are ways to significantly reduce that energy requirement through design choices. One way is by using lighter colors (ideally white), to paint these buildings. There are many white paints for sale that are marketed as “reflective paint”, but all white paints work similarly in that they reflect much of the sun’s rays and, subsequently, the heat. As a result, the interior temperatures of buildings that are painted with white paints are lower than the interior temperatures of buildings painted with darker paints even when they’re in the same area, and the latter requires more electricity to power air conditioning during summer months or in arid climates. Another way builders can reduce the energy spent on heating and air conditioning is by concentrating windows on the South-facing side of their building, unless the building is in the southern hemisphere, in which case they should be concentrated on the North-facing side. This window placement is useful because during the cold winter months, the sun is lower in the sky and more heat is able to enter the building through the windows while, during the hot summer months, the sun is higher in the sky and not as much heat enters through the windows. This technique is called passive solar design; by using the sun’s movement patterns during the different seasons it is possible to make buildings more sustainable. When it comes to maintaining a cool temperature during summer and a warm temperature during the winter, an important factor is the building’s insulation. Most houses use fiberglass insulation, but some are switching to insulation made of silica aerogel because of its decreased thermal conductivity and increased space efficiency. Aerogels have numerous pores, forming a complex maze for heat to go through and making it a very good insulator. In fact, silica aerogel has a higher thermal resistance than rigid fiberglass per inch and even resists flames, helping to prevent the spread of house fires. Small innovations such as these are helping buildings to be more sustainable.

By Ezekiel Gonzalez

April 6, 2026