The decisions you make for your project will have implications on almost any level. Yet choosing a straightforward and reliable build method will help towards simplifying the process. This is where Insulated Concrete Forms (ICF) comes in. If you’re new to self-building you may, (or may not) have heard of it and the benefits it can bring are numerous.
How Does Insulated Concrete Forms Work?
Insulated Concrete Forms consists of two panels of insulating material that combine to create a building block. For years, self-builders have loved the system for its simplicity and speed of build. It is the perfect choice for any project with only five quick construction steps.
1. Choose Your Insulated Concrete Forms Supplier
Not all ICF systems are the same and they can vary depending on the size of the blocks, material and insulation levels. In the UK your ICF block will either be made from Expanded Polystyrene (EPS) or Woodcrete (a mix of recycled woodchips and cement). Speak to a few of our ICFA members to understand which ICF is best for you, they will also provide training on how to use their system.
2. Design Your Home
Despite their dimensions, ICF blocks have the capability to create almost any design – from a traditional farmhouse through to a contemporary home with bespoke shapes or curved walls. This gives you and your architect the opportunity to set your creativity free! Get your supplier involved at this stage in the process, they have the expertise and technical resources to get the most out of your ICF build.
3. Build The Wall
Insulated Concrete Forms have a lot of similarities to traditional brick or block laying techniques that contractors will be familiar with. ICF blocks stack and securely lock together through a raised profile along the edge. The construction process is incredibly quick with a typical standard ground floor layout of a home constructed in only a couple of days. You can use ICF for the entire build whether it’s above or below ground, including basements. In fact, some conditions such as corner windows and cantilevered openings are easier to build with ICF than traditional methods.
4. Pour The Concrete
Walls are usually built in stages, typically ground floor height at first, before concrete is poured into a central cavity in the assembled blocks. Once the concrete has cured the ICF blocks stay in place and construction continues until you achieve full building height
5. Finish The Build
ICF systems easily work with a wide range of standard construction systems, materials and products such as door, floor and roof options. A wide range of facings materials can be applied internally and externally, including brick, stone, render or aluminium, to create the desired look for your home.
How Much Does It Cost To Build With Insulated Concrete Forms?
When you consider the entire process, ICF is a cost effective option. Upfront material costs may be slightly higher, but these are quickly offset by savings made during construction and through ongoing energy savings once you’ve moved in.
The lightweight blocks can be easily moved by hand which reduces the need for expensive heavy plant equipment. The speed and simplicity of the system reduces the number of contractors needed and it may be possible to avoid the highly paid skills of a bricklayer. This can save up to 60% in labour costs on a straightforward single storey course. A watertight shell will be reached much sooner than traditional methods allowing follow on trades to enter and start putting utilities in place earlier in the programme. The build can also continue in most weather conditions avoiding costly delays.
Looking For Sustainably?
At first glance ICF isn’t a particularly sustainable build method due to the amount of carbon created during the production of the concrete. The concrete industry is working towards the adoption of new methods that aim to remove more carbon from the atmosphere than it produces.
It’s also very important to consider the in-use carbon emissions of the building. Studies into ICF structures show that they save far more CO2 over its lifetime than the energy used during construction.
In an ICF building the concrete core sits in direct contact with the insulating block. This creates an airtight structure that delivers exceptionally low U-values, and excellent thermal mass reducing energy usage for heating and cooling your home. Monitored energy usage of semi-detached 4-bedroom home with basement with a useful floor area of 110m2 demonstrates that heating and hot water costs works out as little as £5 per week.
Are You Building In A Flood Risk Zone?
Increasingly, the UK is seeing the effects of adverse weather events. ICF under BS 85500:2015 Flood Resilient Construction guidance is a recommended external wall method. If correctly designed and installed, the concrete structure has no voids and creates a watertight shell. In the event of flood damage, the insulating material in the walls remains water resistant with months of delays caused by drying out avoided.
In terms of avoiding extreme events, the insulated solid wall structure also creates its own natural fire suppression system. Concrete will not burn and can withstand incredibly high temperatures and the solid core in the ICF wall will create an almost impenetrable shell that prevents fire from spreading internally or externally. Most ICF walls offer a fire protection rating of up to 4-hours.
Insulated Concrete Forms – Mortgage Approved
It goes without saying that financing any self-build can be challenging. There are plenty of options available, but you will need to approach companies in advance to understand their requirements. As an Insulated Solid Wall Construction method ICF is considered by the Council of Mortgage Lenders as a standard system if manufactured by an ICFA member.
This article appeared in the publication i-Build
Contact
Use the contact form on the contact page to ask a question or submit an enquiry to all members of the ICFA.