Building an ICF house

We already mentioned ICF quite a few times including the fact that we are building an all-ICF home. So, ...

... what is ICF?

ICF stands for Insulated Concrete Forms. There is a lot of information about ICF available on the Internet. In a nutshell, it is one of the technologies used to form exterior walls of a structure. When complete, you can think of it as a sandwich where foam with high R-value is the sides of the wall and reinforced concrete is in the middle. The foam acts as both thermal and sound insulation while reinforced concrete in the middle gives the wall structural strength. The foam comes pre-manufactured, in a number of standard shapes, where each manufacturer has their own type of block. Something like Lego vs. MegaBlocks. At the construction site, construction workers assemble the sides of the "sandwich", the bracing and reinforcement (rebar) and then concrete is poured in the gap using a pump truck.

Due to high insulating value of the foam, structures built using ICF, if designed and built properly, tend to use considerably less energy to maintain climate inside the structure. At the same time, structural soundness of reinforced concrete protects well against weather conditions and geologic conditions.

So why do not we see all new homes built with ICF? There are several reasons for that. One reason is that, like with all new technologies, there is natural resistance in the construction industry itself. Well-established distribution and sales channels of, for example, traditional wood framing technology make it more straightforward for builders. Another reason is that not as many builders are knowledgeable enough to build with ICF. Less competition means higher markup and higher labour cost, too. Also, ICF only makes sense where its benefits come to work. For example, extreme heat or cold, significant fluctuations in temperature, storms, etc.

ICF - many shades of Green

ICF is good for environment! No, it is not, it uses concrete! Yes, it is, less energy is wasted! No, it uses foam! Yes, it is, better structure means not rebuilding after a hurricane. And so on...

Well, is it green or is it not? As we all know, pretty much nothing is black-and-white. For majority of problems that exist in the real world there is more than one solution. Same with your house's shell. We already brought up some dilemmas about ICF, so let's quickly look at, for example, traditional wood framing. One person could argue that traditional wood framing is green because it uses biodegradable material - wood. However, another person could argue that many many trees have to be cut for just one house's worth of framing, thus undermining environment's ability to fight green gases emissions. Also, if the house is blown away by a hurricane or otherwise structurally affected, it will need to be rebuilt, meaning new trees will have to be cut...

At the end of the day, there is no pure, vivid green. Many factors should be taken into account when deciding what the most environmentally friendly way to build is.

Windows

Next to your house's framing, doors and windows are probably the most important decision to make. There are several reasons for this:

Energy efficiency - Want it or not, this is typically the weakest part of a home when it comes to wasted energy. The better the window the less heat (or cool) escapes through it.
The looks - Doors and windows are an important detail on your house. They can make a house shine or whine.
Cost - Like everything else, good window is going to cost more than a not-as-good one. It is all a matter of trade-off by all means - visual appeal, insulating value, etc.

At this point, we have narrowed the list of suppliers down to two and have to make our decision quickly since rough buck openings will be manufactured shortly. Openings are tailored to the exact window specification but each manufacturer has a little bit different dimensions. Hence the need to move quickly on this one. Our GC Tony Siesto helped a lot, working with different suppliers nailing down details.

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Why all-ICF-house?

In the early stages of planning, among other things, we did a lot of research on shell construction technologies. We looked at it from many different points of view such as:

Energy efficiency - Due to double insulation, ICF is typically high up on the list of choices when it comes to energy efficiency. Do not forget this is Canada. Although, in terms of climate, there are worse places than Southern Ontario, the temperature ranges from -30C (-22F) in the winter to +36C (+97F) in the summer. Good insulation that ICF provides is important to keep heating and cooling cost down.
Impact on the environment - We already discussed this above. There are arguments for as well as against ICF. One other thing to consider here is that reduced energy consumption is always good for the environment.
Cost (one-time cost and total-cost) - In terms of one-time cost, various resources suggest that it is more expensive to build with ICF than with the traditional wood frame. And, from our own experience this is true. However, using solely this difference in construction cost can be misleading. One should also account for other obvious and not-so-obvious costs such as how much energy ICF would save over the years, how prone the location is to natural disasters, how much in terms of construction schedule all-ICF solution might save compared to other solutions.
Construction schedule - As we may have already hinted, lining up one contractor for the entire shell is easier than trying to coordinate multiple contractors for different parts of house's shell. The shorter the construction, the sooner you get to enjoy your new home.

After looking at all of the factors from different angles, we thought an all-ICF house is the right way to go. As far as the ICF block of choice goes, there is many different manufacturers out there but Nudura was the block of choice in our case.

Kitchen

Kitchen design, manufacturing and installation was a part of our construction package. When framing was done we met with designer Les Freud of By Design Consulting where we talked about our requirements and general kitchen layout. We had previously come up with topographical layout of cabinetry, appliances and island ourselves, which made it easier to show Les what we had in mind. Les then turned this into a preliminary 3D CAD model, which he then sent to us for initial comments and corrections. Over the course of a few weeks, we met several times with Les to place and adjust actual virtual cabinets and shelves in the 3D model. During the process, Les' professionalism and experience was evident. Whenever we asked for opinion, Les would always stress whether something was a matter of preference or functionality. At the end, the design was signed off and sent for manufacturing which takes around 6 weeks.

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