Use of natural materials in building construction helps to reduce carbon footprint, promotes biophilic design and brings a sense of connection with nature. They also offer better thermal performance, and improve indoor air quality.
Some of these materials require minimal processing, while others need some. They can be recycled or reused at the end of their life.
Wood
Wood has been a key building material throughout human history. Its strength, tensile capacity and insulation qualities make it an ideal construction material. It is also an environmentally friendly product. Its production produces less greenhouse gas emissions than concrete, bricks or steel. It is also a renewable resource. However, it is important to use wood that has been harvested sustainably. The best way to do this is to look for the FSC or PEFC quality mark.
There are many different types of natural materials that can be used in construction, such as straw, earth and hemp. These materials are renewable, biodegradable and help to reduce the carbon footprint of a building. They are also a good insulator, meaning they can reduce energy costs. These materials are also cheaper than traditional concrete, making them a great option for eco-building.
While the use of natural materials in building construction has been around for a long time, new developments are bringing them into the 21st century. This is especially true of timber construction, which has been growing in popularity as a green alternative to concrete houses. There are a number of timber-building companies that offer both green and sustainable buildings, as well as training for builders. There are also a number of eco-building techniques that are accessible to amateur builders, such as cob, straw bale and timber frame techniques.
Mud
Mud brick, cob, and wattle and daub are all ancient building techniques that use a mixture of earth and sometimes straw. The mix can be pressed to form walls using either hand or mechanical tools. It can also be shaped into arches or domes. While not as strong as bricks made by firing, mud brick can be used to create load-bearing walls. These structures may be single or multiple storeys in height. Mud brick is more flexible than concrete, allowing it to accommodate variations in ground conditions.
It takes much less time to construct a mud brick building than a conventional brick structure. It is a cost-effective option, particularly for those who live in the countryside or cannot afford conventional materials. The material is also environmentally friendly, since it requires no energy to fire and manufacture bricks.
A mud brick house can be more energy efficient than a conventional brick or concrete house because of its thermal mass. However, a mud house needs proper ventilation and humidity control to avoid moisture buildup and damage. Installing exhaust fans and opening windows can help prevent moisture and condensation in the walls. It is also a good idea to monitor indoor air humidity with a hygrometer. Using natural cleaning products can also protect the surface of a mud wall from harsh chemicals and abrasive substances.
Straw
While straw-thatched roofs were common in Europe and the Americas centuries ago, their popularity faded in recent decades as more people began using concrete. Today, however, straw bales are enjoying a resurgence in the construction of homes and other buildings that use natural materials.
Made from a waste product, straw bales are a low-cost, high-insulation building material that requires little energy to produce. Furthermore, they are 100% biodegradable; when the structure is no longer in use, the bales can be plowed back into the soil.
Straw bales are particularly suited to rural areas because they are produced in large numbers close to the site of the home. As such, the construction of straw homes can help reduce fuel bills and greenhouse gas emissions while contributing to local agriculture and economic development. The insulation value of straw bale walls is also very high; according to a study by the British company BM TRADA, they provide up to twice as much protection than a conventional timber-framed building.
One drawback to straw-walled homes is their vulnerability to fire damage, especially if the walls are in a bushfire-prone area. To minimise the risk, builders should continue rendering over the tops of bales and plates so that inadvertent flue effects do not draw air from outside the building to support combustion. Similarly, builders should take care to avoid placing the bales directly on any damp soil or ground.
Concrete
Concrete has a reputation for being hard to build with, but it is actually very versatile. It is also very durable, able to hold up against earthquakes, typhoons, and tornadoes. It can even be used to protect water sources by preventing erosion and flooding.
It doesn’t burn, so it is better for the environment than wood-frame buildings, which can quickly spread fires. It also doesn’t release any volatile organic compounds, or VOCs, which can cause health problems such as asthma and eye or nose irritation. Concrete is an excellent insulator, with a high thermal mass and a low moisture content.
Stone is another ancient and durable natural building material, often seen in walls and monuments. It has a high thermal mass and is very durable, especially when used in thick walls. It is also water resistant and has good acoustic properties.
It can be made with recycled paper and a little cement to create a durable and light material that is also very energy efficient. It’s also an affordable and eco-friendly alternative to wood frame construction. It can be mixed with sand and gravel for strength, or with fly ash and other materials to lower its carbon footprint. It also has the potential to be self-sealing if crystalline admixtures are added. These admixtures are formed by the chemical reaction between un-hydrated cement particles and water to form insoluble needle-shaped crystals, which fill capillary pores and micro-cracks to prevent permeability.