top of page

What are ICFs?

Insulated Concrete Forms are foam block systems (typically EPS) that when installed create a sandwich of foam and concrete.  Standard ICFs have a layer of 2"-3" of foam on either side of a concrete core that is typically 4-6", some have even larger "concrete cores" available.  This system creates the most energy efficient, structurally stable and sound resistant system on the market today.  Other products may advertise a few of the qualities that ICFs offer, but none of those products have everything in one package that has been rigorously tested for many years and is approved by nearly all building, energy, green building and fire codes.


Energy Efficiency is paramount in today's society.  Few products can compete with ICFs.  A standard 2x4 wood stud wall with fiberglass batt insulation will have an advertised R-value of about 13-15.  An ICF wall with 4" of concrete will perform as an R-32 to R-50 depending on the block system & climate.  The reason it is noted as "perform as" is due to the fact that the comparison is not a true apples to apples comparison.  A wood frame wall transfers hot/cold air at a different rate than the foam & concrete due to the Thermal Mass the concrete provides.  R-value is the resistance of heat thru an object.  EPS has a very high R-Value yet concrete has a very low R-Value.  The difference is that fiberglass insulation resists the transfer of heat well, concrete absorbs and then dissipates that heat which creates the thermal mass.  There is more that goes into the physics of how air transfers but that is the simplified version.  A quick Google search will give you a more detailed analogy for those that would like additional technical data. Click on the “Images” button below to see diagrams for a comparison between a 2x4 frame wall and an ICF wall.


ICFs are more than just energy efficient.  They are also in a league of their own when it comes to Natural Disasters.  A 4" core ICF wall will have a fire resistance rating of 3-4 hours and is able to withstand a projectile traveling at over 200mph with little more than a dent (see video below).  Earthquake damage can also can be minimized with the system.  In addition, the blocks have been tested by the military for use in combat areas and have proven to be resistant after numerous ballistic tests.  See our “Safe Design” page for more information about this.


ICF's are rapidly gaining popularity due to their structural integrity, ease of use and energy efficient design. RKD is recognized as an industry leader when it comes to designing structures with ICF systems. This experience will save you time and money during the construction process.  Lower on this page there is an example of an ICF project and how we helped a client save over $70,000 on their home.  With many different ICFs on the market, let us help you evaluate and decide which system will work best for your next project.

We specialize in ICF design

“Concrete homes will revolutionize American life.  They will be fireproof, insect-proof & easy to clean.  Extra stories could be added with a simple adjustment of the molding forms.  Best of all, the $1,200-dollar houses will be cheap enough for even the poorest to afford.”
 ---Thomas Edison, 1906
ICF Challenges

ICF Challenges

ICFs can be one of the best choices to use when building any new structure, However, we all know that nothing is perfect.  When you understand the challenges, the more likely it is that your project will succeed.  One of the biggest challenges we see time after time is Structural Engineering.  This happens when you have an engineer that is not familiar with the systems or one that is apprehensive to engineering anything but frame or masonry construction.  When this occurs, they have a tendency to take on the attitude of if 1 is good, 5 is better.  When this happens, it will cost YOU more money.  The following is a real project we had and is a prime example of this happening.


A few years ago we had a potential client that discussed a new 3,500 square foot custom home with us and he wanted to use ICF.  We explained the pros and cons and showed him different types of block systems.  He chose a system he liked and we started the design.  The design was very unique and it was for a lot that had some hillside challenges.  When it was time, we recommended that he use an engineer that we have worked with many times on ICF projects.  However, they had an engineer that was an acquaintance and wanted to use him instead – we explained the challenges but in the end we followed the adage "the customer is always right" and proceeded with their engineer.  The plans and engineering was completed and the project went out for final bid & when the bids came in the project was over budget by nearly $75,000.  The client was upset and wanted to kill the project.  I persuaded him to give me a week to find out what the issue was.


I met with the general contractor and he stated that the majority of the overage was in the concrete and rebar per the engineering specifications.  Upon learning this, I immediately had the original engineer I recommended review the plans.  He came back with a solution – he would re-engineer the plans and if he didn’t shave at least $25,000 off the budget he wouldn’t charge for his services.  The client agreed.  The plans were engineered again then re-bid.  The design of the home didn’t change and when the new bids came in, the reduction for the labor, concrete and steel was nearly $70,000.  The owner further helped the budget by selecting less expensive finishes, cabinetry, plumbing and electrical fixtures – this added another $30,000 in reduced costs totaling $100,000 reduction from the original bid.


This proves how important having the right team is integral to any project.  While a few dollars may be saved early on, it could result in thousands in unnecessary fees later on.  

ICF Videos by Robert Klob Designs

ICF Videos by Robert Klob Designs

ICF Videos by Robert Klob Designs
Search video...
Flying Debris Cannot Penetrate ICFs
Play Video

Flying Debris Cannot Penetrate ICFs

ICF Install 1
Play Video

ICF Install 1

Robert K
ICF Install 2
Play Video

ICF Install 2

Robert K
icf vids
It's true - “any” design professional can (and should) design with ICFs.  However the staff at Robert Klob Designs has more ICF design experience than just about anyone else in North America.  We have the knowledge and understanding of all of the 30+ ICF systems found in North America.  This experience will assist your contractor in avoid challenges in the field - and saving you money.  This is combined with our involvement with the development of the ICF building codes, assures your project is designed correctly, efficiently and cost effective from the beginning.  Both your house and your designs should start with a good foundation.  
We also realize that we can't design every ICF home.  For those who prefer to work with your own design professional, we provide ICF consulting services.  If you already have plans and would like us to review their quality, please contact us.  See our SERVICES page for more information.
A few of our ICF Accomplishments & Qualifications........

Designed or consulted on over 400 ICF homes & structures in several states & countries.

Member of the Development Committee to write the ICF Building Code.

Provided free ICF plans to disaster victims after tornados and hurricanes.

Helped several ICF companies develop/refine their construction details.

We KNOW the systems, their strengths & weaknesses, and the best people to work with.

We are familiar with the different manufacturing facilities, their locations and how to keep transportation costs down on your job.

We can help find the installers and contractors in your area that are familiar with ICFs and offer the highest level of service.

We have seen and resolved more problems than most Design Professionals even know exist - and how to avoid them on your job.

Certified installer for several ICF brands.


ICF Trainer for Architects, Engineers, Contractors, Building Officials & Inspectors.


Founding member of the ICF Builder Group - the industry trade organization.

Why use RKD to design your ICF Home?

Why Use RKD

This list is in alphabetical order.  We have substantial experience with these companies and can easily recommend their product and/or their customer service.

Plus MANY Others!

With over 30 ICF manufactures, how do you know which is the

right one for your  project?

We have designed or consulted with most of the systems available.  With this unequaled  experience, We will help you select the best ICF system for your project!

ICF Block Manufacturer Links

Our Friends at ICF Builder Magazine have developed a great resource to compare

each of the ICF brands.  


Click on the button to download the file.

ICF Links
bottom of page