2×4 vs 2×6 Exterior Walls: The Great Debate

Initial Thoughts

As the world and the USA become more eco-conscious, designing your home to be more energy efficient is becoming not just popular but a necessity.  Though a 2×6 wall offers more insulation which, of course, leads to a savings in utilities, is it really worth it?

The Breakdown

Here in Texas, the majority of the time we need to keep our houses cool, in order to figure out if two inches of added insulated will significantly save you money, you need to think about your location and the cold days that you experience.  The University of Illinois Building Research Council determined that there are two factors to saving energy.  The first is how far above sea level do you live?  In San Antonio, we are about 772 feet above sea level.  Because the air near sea level is denser, heat travels faster between air molecules, every 1000 feet above sea level, heat loss by conduction is reduced by 5 percent.

Now, let’s look at the second factor: how long is the cold season and how low does the temperature get?  The degree day method is the best way to measure this in your city: add the high and low temperature for each day in a year then divide this by 2.  Take this number and subtract 65 for each day.  If you end up with a number that is higher than 5750 then 2×6 walls would be significantly energy efficient, the higher above that number, the more energy efficient your walls would be.  The initial costs will be high, keep in mind that you will have higher upfront costs for top and bottom wall plates, wall studs, window and door extension jams, and insulation.  Ask your custom home builder to show you the difference in costs between a house that uses 2×4 and one that uses 2×6 exterior walls, from there you can compare your energy savings to your upfront cost.

Final Thoughts

Location, location, location.  You’d be surprised how much your home’s location comes into play when making choices about your building materials and design.  The importance of talking to your custom home designer or architect about their recommendations cannot be stressed enough; their experience and knowledge can help you make the right choice for your area.