How we're building an energy efficient home that will cut 50%

Question

Hi all, wanted to share with everyone energy efficient improvements that you could implement while you are building a new home. These improvements will cut your energy bills by 30% or more and you will get the best ROI

https://www.youtube.com/watch?v=Pn4w9k6shSQ

Pavel Sakurets · Answer

Hi Nate, yes zip wall sheeting acts as an air barrier and water barrier. Just to be safe, even though a house wrap is not required in zip system, I'll install it anyway, because I'm concerned about proper flashing around the windows. Zip system says that you could tape a  window flashing to the wall surface by using the tape, but I'm afraid that with time the tape will peal off; installing house wrap will create an even water barrier and will allow to install the flashing under the house wrap. For $1300 extra that I'll spend on house wrap and labor, I don't want to take the risk.

I have not built multi family yet from scratch, but my company has gutted and remodeled several buildings in uptown Mpls that were converted into condos.

I know of only one multi family developer in the Twin Cities that understand the concept of exterior foam insulation and reduction of thermal bridging who uses zip wall system.

Yes, you pay more upfront, but if you plan to keep the building for 5-7 years you recoup the entire cost of zip wall system by paying less for heating and cooling.

In commercial construction, smart developers used exterior foam insulation since 1980s, I had a building in Hopkins that had that. However builders build what architects spec out and most of the time exterior walls will have R7.5 foam with hollow metal studs that loose a lot of energy due to high conductivity loss. In my opinion, if builders use at least 4'' foam on the outside, it will improve heat loss by more than 50%.

Unfortunately when people buy houses, they buy the looks (granite, nice flooring, appliances, etc) and don't pay any attention how much it costs to operate the building. Hopefully this will change soon.

Pavel Sakurets · Answer

Thx Nate, I checked with Zip people and was told that it would not cause any issues if I install a house wrap that can breeze. (Most likely I will do Tyvek. Before I was using Typar, but the red tape doesn't stick to Typar)

Pavel Sakurets · Answer

Mike, we only spray the rim joists with foam (rim joist is the area where trusses are laying on the outside walls between the floors) If you spray foam the entire house with foam, you will need to install sound proofing, because sprayed walls transfer the sound faster than windows. In addition, to spray foam the house with foam on 2000 sq ft home will cost additional 20k, and spraying the walls doesn't resolve the issue of heat transfer through the studs due to conduction method of heat transfer. Thus, exterior foam insulation is the best method with regular fiberglass insulation from the inside. Has the highest ROI

Nate Wightman · Answer

@Pavel Sakuretsbe careful with the vapor barrier over a zip wall barrier  might check with zip wall first and make sure you do not create a trapped zone where moisture can not get out  ... enjoy this post...thanks

Jeff Martin · Answer

@Pavel SakuretsReally interesting stuff. Alternative and green energy are big areas of interest for me that I would like to incorporate into my RE business once it is more established. It almost seems like a competition in a lot of new construction to see who can build the highest efficiency. Love it!  Thanks for posting!

Mike Makkar · Answer

@Pavel Sakurets, the numbers make sense. There's also potential to improve the value of the house, if its appropriately marketed. If the next buyer is going to be spending 250 per month less, then essentially is getting 25k more value. Half that, could go into the appreciated value of the house.

What about the question on spray foaming the walls of the rest of the house? Is that something you guys will be doing?

Pavel Sakurets · Answer

Hi Mike, a typical 4000 sq ft home in MN will consume on average $100 per month of electricity  (about 800 kwatts) and $500-$600/month for gas in winter, $300/month in the spring and fall and $60/month in summer for water heating, cloth drying and cooking. Thus $4000-$4200/year=$333 month. Which is $433/month for heating and cooling.

I'm estimating this home will use less than $250/month on average for heating and cooling, saving $150-$200/month or more. If we spent 30k more for energy improvements, the pay back will be within 12.5 years or less (assuming that energy prices do not go up).

For smaller home \, you could spend 15k more and get the same pay back. The home that I showed in the video is 4000 sq ft

Mike Makkar · Answer

@Pavel Sakurets, really good video! I'd be interested in per monthly cost savings for such a $10k to $15k added investment. I think that's what you mentioned in the beginning of the video.

Also, any reason why you are not applying spray foam insulation across all of the walls and just only the basement floors? Cost prohibitive?

Again, thanks for posting. I'm curious if you have ideas on making existing homes more energy efficient.

Sarah Masteller · Answer

Thank you for posting - I enjoyed the video!

Cody Barrett · Answer

Wow that is really neat. Love it! Efficiency is always a win!