Insulated Concrete Formwork in Building Design

Understanding insulated concrete formwork in sustainable building design  

Offering the chance to develop high-quality dwellings with a lifetime of low-running costs, insulated concrete formwork (ICF) is a common building solution if you value sustainability over short term savings. Here, we take a look at ICF and why more and more developers are favouring this construction style.  

What is insulated concrete formwork? 

Insulated concrete formwork, or ICF as it’s often known, is a construction method that involves pouring concrete into hollow insulated forms. These forms stack atop one another and hold their position without the need for mortar. When the framework is complete, concrete is poured into the voids between the insulated material. Once solidified, this combination of concrete and insulation provides a sturdy and thermal-regulated shell for the building that helps to deliver energy efficiency in all seasons. 

Several types of ICF system exist, but three methods in particular are most common in the UK. These are: 

• Expanded polystyrene (EPS panels) 
  An ICF system that involves manually joining two separate EPS panels together to form one block. 
• Expanded Polystyrene (EPS) Moulded 
  Pre-formed blocks that are immediately ready to use. 
• Woodcrete  
  A type of chipped wood fibre insulation that’s a by-product of waste wood. The wood fibres are mineralised together and bonded with cement to form a block. 

What are some of the benefits of insulated concrete formwork?  

ICF or insulated concrete formwork is considered relatively sustainable compared to other traditional construction methods like concrete blockwork or brick construction.  

The key sustainability benefits of ICF include:  

1. Energy efficiency 
   ICF construction provides a continuous, airtight insulation layer, both inside the dwelling and on the exterior of the building. This double insulation effect reduces heat loss in winter and limits heat gain in summer, helping to regulate the building’s temperature more effectively. This thermal regulation ability reduces the burden on manmade heating and cooling systems, such as gas-powered boilers and air conditioning. As a consequence, the dwelling consumes less energy and emits fewer greenhouse gas emissions, leading to lower energy bills and a smaller carbon footprint.  
2. Reduced waste 
   ICF is made of lightweight materials like polystyrene, or waste materials like chipped wood, the use of which produces significantly less waste than traditional concrete construction methods. The system is suitable for construction both above and below ground, making it suitable for developing strong and stable foundations, in addition to retaining walls. In certain instances, it can actually be easier to construct a building using the ICF system over other construction styles. Corner windows and cantilevered openings are two such architectural design features to which this applies.   
3. Recycling and reusability 
   ICFs offer builders a further sustainability benefit in that they can be recycled at the end of their life cycle and repurposed for other uses. The system relies on fewer materials than comparative construction methods, and several ICF suppliers actually manufacture their blocks and panels using recycled materials, such as a type of low carbon cement that’s derived from steel industry waste. With few exceptions, nearly every ICF material can be recycled using current recycling methods, so, should the building be decommissioned and pulled down for any reason in the future, its core component parts can be given a new lease of life, instead of being condemned to landfill.   
4. Cost-effectiveness 
   ICF can reduce construction times, allowing developers to turn out homes faster than traditional building methods allow. The system relies on a skillset closer to carpentry than bricklaying, but the resulting finish is also of a much higher quality than can be achieved through more commonplace construction practices, lowering the need for maintenance throughout the property’s lifetime. And it’s not only developers and builders who reap the cost-effectiveness of insulated concrete formwork dwellings; the energy efficiency of these buildings also means that those purchasing an ICF home will benefit from lower energy usage and, consequently, cheaper fuel bills.     

The application of ICF in sustainable building design 

With a greater emphasis in the UK on improving energy efficiency, the ICF method of construction is often a proactive choice for compliance with modern building regulations and advance towards better efficiencies.  

ICF dwellings can be constructed faster than traditional buildings, and offer buyers lifetime energy savings, also making a compelling case for increasing the use of ICF within the British building sector. One thing is for certain, with consumers more conscious of their environmental footprint and actively looking for ways to cut back on their energy usage, ICF buildings present a very desirable option that delivers a multitude of benefits to both developer and buyer.  

It is worth noting however, the sustainability of ICF can be dependent on the specific materials and manufacturing processes used, as well as the location in which they are used. Therefore, careful consideration should be given to the environmental impact of ICF in each specific project. 

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