Exploring the Use of Organic Materials in Building: Beyond Hobbit Homes and Basic Mud Structures
In the pursuit of a greener and more sustainable future, the construction industry is increasingly turning to natural materials. This guide focuses on the benefits of these materials for sustainable construction.
One of the most common natural materials used in construction is wood, or timber. Known for its lightweight and insulating properties, wood requires less water and energy compared to many other materials, resulting in a lower carbon footprint. Renewable when sourced responsibly, wood does require treatment for moisture resistance and pest protection.
Bamboo, a fast-growing grass with a woody stem, is another sustainable option. It can replace up to 70% of steel in applications, making it a strong, renewable alternative. Bamboo forests sequester about 1.33 times more carbon per hectare per year than tropical rainforests. However, treatments to enhance durability in humid climates can raise its carbon footprint unless eco-friendly methods are used.
Natural stones like granite, marble, travertine, and limestone are durable, waterproof, and visually appealing. They have good temperature resistance and add longevity to structures. While their extraction has environmental impacts, their longevity and minimal maintenance help with sustainability in long-term use.
Natural insulation materials, such as wool, hemp, and cork, are also gaining popularity. Wool regulates humidity, is fire-resistant, and effective even when damp, aiding energy efficiency. Hemp is carbon-negative, breathable, fire-resistant, and reduces energy consumption. Cork, harvested sustainably without cutting trees, provides excellent thermal and acoustic insulation and is fireproof.
These materials offer sustainable benefits by being renewable, carbon-sequestering (like bamboo and hemp), energy-efficient (insulating properties of wood, wool, cork), and durable with low maintenance requirements (stone). Their use reduces dependence on high-energy synthetic materials like concrete, steel, or plastic insulation, helping to lower the environmental footprint of construction projects.
In the UK, timber frame methods have become increasingly popular, with one in every three detached homes built using this method by 2014. Weather conditions in a specific location should be considered when choosing materials for construction.
Mud has been the world's primary building material for 10 millennia and is still being used by one-third of the world's population for housing. The first mud-based mix used for construction (cob) can be traced back to the 11th century in northern Africa. Mudbrick, also known as 'Adobe', is a sustainable, locally available material that can reduce carbon emissions and costs associated with transport.
In an urban environment, materials should have sound-absorbing ability, optimize indoor air quality, and regulate temperature. Raw earth has 1/40 the carbon footprint of concrete. Europe produces 144 million tonnes of straw as a waste product from wheat every year, and straw can sequester up to 1.35 kg of CO2/kg.
Natural fibres, such as hemp, jute, and kenaf, are commonly used in developing interior architecture elements like workspace panels and furnishings. Hemp currently makes up less than 0.5% of the 3.3 million tonnes of insulation materials used annually. Hempcrete was developed in France in the mid-1980s.
France is still leading the way with the most construction projects using hemp, but other countries like Portugal, where cork oak forests cover roughly 2.1 million hectares, with a third in Portugal, are also making strides in sustainable construction. Portugal's cork industry represents 1% of the country's GDP with annual exports totalling over €1,346 million.
Architects, planners, designers, local authorities, and individuals can make a difference by choosing appropriate materials. The cost of natural fibre production is much lower than for traditional fibre materials, and the size of the project should be considered to ensure the availability of materials.
Estimates suggest that natural fibre prices will remain low, likely below €1/kg. The guide provides information on several natural construction materials, including wood, straw, mud, hemp, and cork. By embracing these materials, the construction industry can contribute to a greener future.
References:
- Academia.edu (2021). Natural Materials for Sustainable Construction. Retrieved from https://www.academia.edu/45248039/Natural_Materials_for_Sustainable_Construction
- Bamboo.org (2021). Bamboo in Construction. Retrieved from https://bamboo.org/bamboo-in-construction/
- WoodworkingNetwork.com (2021). Sustainable Wood Products. Retrieved from https://www.woodworkingnetwork.com/sustainability/sustainable-wood-products/
- HempToday.net (2021). Hemp in Construction. Retrieved from https://hemp today.net/hemp-in-construction/
Science plays a significant role in the investigation of climate-change implications on the environment, particularly in the context of sustainable construction. For instance, technological advancements have been instrumental in the development of eco-friendly materials such as hempcrete and bamboo utilization in construction, thereby reducing the environmental footprint of the industry.
