Tuesday, February 15, 2011

Are ICF foundations better that others???

First of all, I'd like to say thanks to all who came out to the Rochester Area Builders Home Show this past weekend.  It was a huge success and we had excellent traffic.  In last years show, I built 2 custom homes for clients I met at the event.  I hope to duplicate that this year and it is really looking positive with the feedback from the potential clients we met there.

One of the many topics this year that I had come from the people visiting my booth was regarding ICF foundations.  Although many opinion may differ, they are not my choice for a couple reasons.  The first being the added cost to the homeowner.  In todays environment with appraisals being so difficult, this can be a factor right out of the gates for people.  If the cost of the home is higher than the appraisal, other parts of the home need to be sacrificed in order to get the ICF's into the budget.  The other problem I have with them is the mis-information on the efficiency.  I think they are a great way to make a home efficient if they are taken all the way to the roof trusses(this is an extremely expensive way to use them), but if they stop at the foundation they are not.  The State of MN has conducted studies proving that having more than R-5 insulation below grade is not necessarily a good thing.  In MN, the average ground temperature is near 55 degrees all the time as long as it is below the frost line.  55 degrees can be good in the summer or the winter.  I think of it this way.  If in the summer it is 100 degrees outside and that temperature is trying to get into the home, having the 55 degree ground temp is good to allow the ground around the home to absorb the homes ever gaining heat.  The opposite happens in the winter.  If it is -10 degrees outside, the home is constantly taking in the 55 degree heat from the ground around the foundation.  If the insulation level is higher than R-5, this cannot occur as easily.  I look at this type of system as a built in Geo heating system.  This is the reason I build my homes with an R-5 exterior insulation.  By placing the foam insulation on the exterior, we move the condensation point to the exterior making the basement feel warmer yet.  One last thing I recommend to my clients, but few do is to foam 4 feet away from the home to just below grade.  This will prevent the frost from actually diving down on the homes foundation and keep the entire foundation wall at the magic 55 degree ground temp.  This along with placing retaining walls in all areas that the foundation has taken a jump will keep your new home and its foundation working the most efficient way possible.  I'm sure this is an area where many can and will disagree with me, but with my homes scoring on average less that 59 on the HERS Energy Star Scale it is hard to discredit.

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