Reader Question: What’s the Best Insulation for my new home?

Home Reader Question: What’s the Best Insulation for my new home?

I’ve been blogging now for about 5 years but it’s just been in the last 6-12 months that my readership has really been on the rise. I get about 1-2 emails a day from someone who has a question about a post. So, I thought I’d answer one of them here… Lance emailed me from Baton Rouge, LA and asked me what insulation I thought he should use in his new home and what my thoughts were about Geo Thermal Heat Pump systems.

So, before I answer the question let me revert you back to the Pyramid of Priorities. Green Builder Mag published this a while back and I really like the idea of doing the simple stuff before doing the hard (but sexy) stuff. For example, how cool are Solar Panels? Way COOL! But, if you’re not doing the basics correctly on the passive systems the expensive active systems can be a waste. I’m not totally sold on Passive Haus standards of super insulation, but I do think that houses should be insulated much better than today’s energy codes dictate. To answer Lance’s email about insulation here’s my recommendation:
– Frame the house with 2×6’s (24″ OC if possible)
– Insulate the walls with Owens Corning Energy Complete which is a two step system. Here’s a past blog post on that insulation system.
– Use 3/4″ Rigid Insulation on your outside walls, and 2″-4″ of Rigid Insulation on your roof deck.
– Lastly, spray foam your attic with 5.5″ of open cell foam to create a conditioned attic.
This will far exceed 2015 or even 2020 Energy Codes, and make a very temperate house in our hot/humid climate. My clients with this system have very low energy bills and there is nothing to break, wear out, or maintain.

Ok onto the question about Geo Thermal systems. First, let me say that I’ve not done one before. My HVAC contractor that I use has done quite a few of them and I have lots of third hand experience. They are exciting and efficient but there is lots of parts that need to be installed perfectly to operate with the stated efficiency. I’m always concerned about durability and maintenance and I’m not convinced they are worth the money. In my opinion, they extra money spent on this “Active” system would be better spent on “Passive” things like better insulation/windows/roofing/air sealing, etc. I would rather use a high efficiency standard HVAC system that’s been proven over time, is very reliable, easy to install, easy to maintain, and if it breaks down anyone in town can service it. -Matt Risinger Risinger Homes