What construction businesses need to know about natural building materials

Buildings account for a significant portion of the UK’s total carbon emissions and the construction process is a major factor in that total figure. Much like other trades, there’s now a drive to raise sustainability and limit construction’s impact on the environment.

The materials used during the build process are no exception to these efforts and most manufacturers are now producing greener products to limit the amount that ends up in landfill or incinerators.

Customers are becoming increasingly conscious of their purchasing habits and how they affect the environment. As such, it makes sense for businesses to be aware of the alternatives out there and how they can replace traditional approaches. Read on as this guide takes you through everything you need to know to start building greener.

In a hurry? Scroll down to the FAQs section for a quick overview.

 

What construction companies need to know about natural building materials

Natural building materials use less energy when being produced. They will also be made of recyclable products, or be re-usable or bio-degradable at the end of their life. They are also less likely to emit toxic volatile organic compounds (VOCs), which ate harmful chemicals found in traditional building materials. VOCs are linked to a number of health effects, such as Sick Building Syndrome.

It’s rare to find housing developments made from only natural materials. But it’s possible to swap out many traditional materials in place of more sustainable ones, which can help to lower the amount of ‘embodied’ carbon in a build. This is the emissions total that’s calculated from all the energy used during construction.

 

How to build sustainably

It’s not difficult to prioritise sustainability into your building design plans, so long as you start planning from the start. Through the careful choice of building materials and construction methods, you will be able to build greener homes that bring a number of benefits.

It’s a common issue for buildings to be built with too little insulation, so be sure to use enough. The more insulation you incorporate into the structure of a home, such as the walls, roof and floor, the more heat it will retain and the more efficient it will be when in use. If you are particularly interested in insulation methods and considering starting a business in this line of work, check out our guide here.

Your building design should also factor in airtightness. Fewer gaps and cracks in a home’s structure means less heat is lost to the outside as a result. Many natural building resources also offer good insulation and should be used as much as possible. This will improve thermal performance and is less hazardous when compared to fibreglass-based products.

Greener materials are a simple way to raise sustainability when building a more environmentally friendly house but are often overlooked. While sometimes more expensive, the typically perform on par or better than more traditional options so it’s worth doing your research first.

 

Sustainable construction materials list

Wholly natural building materials include:

• Timber
• Clay
• Wool
• Cob
• Straw bale
• Cork
• Hemp
• Reclaimed materials
• Lime
• Stone
• Marble

It’s important to note that things like iron, aluminium, glass and concrete aren’t classified as ‘natural’ despite being made from naturally occurring materials. This is because it takes so much energy to turn them into something useable.

Sustainable materials in construction

Timber

Timber is the most commonly used natural building material and is incredibly versatile. It has widespread application beyond the timber frame of your build. It can also be used for cladding and joinery, as well as for all kinds of internal finishes and flooring. It’s durable, structurally strong and surprisingly fire resistant. Timber can sustain very high temperatures without collapsing and is very effective for absorbing loud sounds – consider this when building in densely populated areas.

Be sure to carefully specify the timber for your build as this will ensure it’s sustainably sourced from properly managed forests. To identify sustainably harvested timber, look for the FSC mark. When you need a surface finish, look for natural paints and stains made from plant-based resins, oils and dyes. These will biodegrade when disposed of, and little energy goes into their production.

Cob

Cob is a mixture of sand, clay, and straw, bound together into a material which can be used to sculpt a home. Cob is pressed in such a way that there are no gaps or cracks, and it can be applied over a concrete or stone foundation.

Cob is virtually a zero-carbon home build, with the only emissions coming from the fuel for a digger. Cob walls are really thick, which means it’s not an ideal build method for a small plot, but it does result in a very thermally efficient home.

Straw bale

Straw is a by-product of agricultural production and of low value. What’s more, building with this material is quick and easy as well as having the added benefit of being fire-resistant. Straw can also be used as an infill material to work alongside a timber frame and provide highly efficient insulation.

Straw can be used in a similar way to bricks, or as a supportive material for the roof. It’s generally finished with lime render and lime or clay interior finishes, creating a breathable fabric that regulates indoor air quality and keeps damp at bay.

Cork

Cork is a naturally occurring material that is sustainably produced, and is already used for many internal applications such as flooring, as well as eco-friendly cladding. Cork is also starting to be used as a building material for walls and roofs.

Hemp

Hemp is easy to grow, so can be used abundantly at a low cost. This material is generally used for walls, floors and roof structures. It’s also used to form hempcrete which is emerging as an eco-friendly alternative to traditional concrete. Hempcrete is made with fibres from fast-growing plants mixed with lime, resulting in a strong but lightweight alternative.

Reclaimed materials

There are lots of waste materials that are left unaccounted for within the construction industry, but these can in fact be reused for building projects.

Resources that come under this category include salvaged wood, materials from doors and windows, piping and chunks of concrete.

Lime

Lime is a durable material that can be used for plasters and renders. Unlike cement, it’s breathable and can be an effective finish or binder for other natural building materials. Old lime putty, plasters and renders can even be removed, soaked, remixed and reused.

Innovative sustainable building materials

The UK needs to build 300,000 homes a year to meet government housebuilding targets but it also needs to do this with ‘net zero’ emissions targets in mind. Unsurprisingly, this is driving innovation in the eco-friendly building materials market.

Wood, for example, can now be treated and compressed to become transparent. This creates a strong and environmentally friendly alternative to glass and plastic, and has the strength of lumber but is much lighter. This method is also ideal for improving levels of light inside a property.

Discarded cigarettes are another interesting development. They account for a high volume of the UK’s waste each year, but researchers have found they lower the amount of time and energy required to bake bricks ready for construction. The cigarettes are added to the brick mixture before the baking process, resulting in a lighter material with better insulation properties.

These developments may sound insignificant, or even bizarre, but they are the types of small improvements needed to chip away at construction’s overall environmental impact.

 

Sustainable construction methods

Sustainable construction isn’t limited to just using eco materials. It also involves adopting better methods of working and some of these include:

• Cutting materials carefully and precisely to reduce waste
• Controlling waste management by separating and recycling waste
• Constructing green buildings
• Adaptive re-use projects, for example those that transform old buildings
• Managing construction sites to improve the environment
• Conserving energy
• Selecting sustainable and recycled materials

 

FAQs

What are sustainable building materials in construction?

The use of natural, renewable, low-carbon materials for buildings. These include natural fibres and abundant mineral resources. For example, straw, timber, cork and cob are used as structural fabric, insulation and finishes in buildings, both in retrofit and new build.

What building materials are most sustainable?

Timber is often regarded as the most sustainable building material within the construction industry. Possessing a low-carbon footprint, it can be used as a replacement for steel and, in some cases, concrete.