Building Methods – ICF vs CBC

Building Methods

ICF Construction versus CBC


Previously JEArchitecture posted a blog introducing a modern form of construction know as Insulated Concrete Formwork or (ICF) and described its benefits and its draw backs. This blog can be found here. Moving on from this we will compare it to a more traditional form of construction, that being of Concrete Block Construction or (CBC). At JEArchitecture we have completed a few new builds with even more currently on site which are using ICF as a construction method.


These builds can be found here and will be updated with Finished photos soon.

·       St.Margarets new Build

·       Delahassy Extension

·       Barn Build Lusk


Concrete Block Construction (CBC) and insulated concrete formwork (ICF) walls have many features in common as a construction method such as –

·       Energy Efficient

·       Durability

·       Good Indoor Environmental Quality


However with a specialist in ICF construction, ICF can be a quicker and easier construction method in comparison to the traditional method of CBC, which at the end of the day will save our clients’ money during the building process.


Both CBC and ICF are mass wall construction systems which we have used in residential construction but can also be used in commercial projects. Mass walls provide our homes with energy efficiency through mass rather than purely on insulative values alone. This mass will store energy throughout the day and release it back into the building during the night.


The simple advantage of ICF over Conventional CBC construction


There is one significant difference between ICF and CBC construction. Building with insulated concrete forms, can be faster and simpler than CBC construction. Therefore, ICF wall systems can save money, reduce labour, and lessen construction risks over CBC wall systems and include interior and exterior continuous insulation to all walls built with ICF.


What is Concrete Block Construction?


CBC is concrete block made from cement, aggregates like stone and quartz, and water. The blocks come in an assortment of shapes and are hollow or solid, with two or three cores or voids.


Advantages of CBC Construction –


There are several advantages of CBC construction, including:


  • CBC is resistant to moisture, rot, and mould and are durable.
  • CBC is fireproof and can act as a firewall between rooms or structures.
  • CBC is pest-resistant.
  • CBC is a good sound-proofing material.


What is ICF Construction?


Insulating concrete form or insulated concrete form (ICF) is a system of formwork for reinforced concrete usually made with a rigid thermal insulation that stays in place as a permanent interior and exterior substrate for walls, floors, and roofs. The forms are interlocking modular units that are dry-stacked (without mortar) and filled with concrete. The units lock together somewhat like Lego bricks and create a form for the structural walls or floors of a building.


 ICF construction has become commonplace for both low rise commercial and high performance residential construction as more stringent energy efficiency and natural disaster resistant building codes are adopted.


The basic principle, though, is very simple – even elegant. Large, hollow, lightweight polystyrene blocks (a bit like Lego bricks), lock together to create instant formwork, that is then filled with concrete to make structural walls.


Advantages of ICF Construction –


  • Quick. 
  • Cost-effective
  • Immune to bad weather. 
  • Strong. 
  • Good thermal performance. 
  • Improved acoustics. 
  • Fire-retardant. 
  • Heat storage. 
  • Flexible design. 
  • Chasing for services. 
  • Can be clad externally with any material. 
  • Very little waste. 


A more detailed explanation of the above advantages for ICF can be found on our previous blog here.


Advantages of ICF over CBC Construction?


The goals of both ICF and CBC wall construction systems are to produce durable, energy-efficient, storm- and fire-resilient wall construction for the required project. The two wall construction types also aim to create a comfortable and healthy environment for the occupants of the building or home.

However, similarities between ICU and CBC part ways in the ease and efficiency of the two building methods. Insulated concrete form can take much less time to build over concrete masonry unit walls.

There are a few reasons why CBC walls take longer to construct than ICF walls.

·       CBC walls require the placement of mortar between all horizontal and vertical joints and then need to be finished. ICF walls are put together like lego. No mortar, extra tools needed.

·       Sizing and handling –  1 ICF block is equal to 6 CBC blocks at a fraction of the weight.

·       Unlike ICF walls, a CBC wall needs an application of insulation. Applying insulation over the concrete masonry wall involves a second trade to the project site. The second trade can add more costly labour to the construction project.

·       A concrete masonry wall often requires the installation of an air and moisture barrier, which adds another trade and more labour to the wall construction project.


At JEArchitecture we can discuss various construction methods with our clients and advise on the best solution for the project and the budget. We have experience in many different construction methods and a list of contractors who can carry out these various construction types, who we trust and value their work quality.


If you would like to discuss your project with please feel free to contact us as we would be more than happy to help you in this regard.