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Passive House Update – Zehnder ERV, Insulation Time, Blower Door Test!

I promised you an update on our Passive House progress in February and it looks like I failed because March is here already!  Since February was such a short month, I guess you can still consider this February’s update.  The good. The bad. The ugly truth.

passive house update, march 2015 simplifylivelove

Passive House Update – Zehnder ERV, Insulation Time, Blower Door Test!

Getting to Insulation

I had hoped to have pictures of drywall for you at this point. Sadly, I do not. There’s just been so much to do to get to that point. We’re getting closer – but we’re just not quite that far along yet.

But that doesn’t mean people haven’t been working on the house since my last post. Someone {us, the plumber, electrician, and/or HVAC guys} has been working on our house almost every single day since I wrote the last update. We’ve honestly made more progress in the last month than we made in the last six months combined.

passive house update - electric water heater and zehnder erv parts

The electrical, plumbing, & HVAC are pretty much finished. Our house is 100% electric – heating, cooling, and water heating as well. We decided on 100% electric because we plan to generate our own electricity at some point with a solar generating system tied to the grid, and venting holes for gas can be hard on the passive house model. Dan and I both pulled electrical wires (he did more than I did), but we were excited to pass our electrical rough-in inspection last week – super good news!

Our plumbing system also has some unique features as our showers and bathtubs drain separately from other water pipes so we can reclaim the heat out of the waste water. We will also run a grey water line out to my garden to provide irrigation! Pretty cool, huh?

passive house update - 5 months to move in zehnder ERV arrived

Zehnder ERV

Hugely exciting news (as far as my husband is concerned), the Zehnder ERV (energy recovery ventilator) system showed up from Germany last week and is almost completed installed – a pretty big accomplishment since the instructions arrived in German. {And yes, you may recall that I grew up speaking German; however, technical German is not my forte.} This Zehnder air system is critical to the passive house (PH) model as it keeps the indoor air quality high by bringing in fresh outside air, heating it up a bit if it’s really cold, and then distributing it around the house. It’s pretty crucial that a tightly insulated home has a way to keep air quality high. We don’t want to end up with a nasty, moldy mess in our house.

passive house update - march - zehnder erv pipes

Fortunately, the PH model takes the mold issue most seriously and is supposed to have the highest indoor air quality of most houses. The Zehnder ERV is the magic system. The picture above shows the air delivery pipes that take in fresh air and deliver it to every room in the house. The studs had to be cut and the pipes had to be threaded around all the exterior walls. I think it looks like something out of a Dr. Seuss book or some type of sci-fi. It’s really one of the weirdest things I’ve ever seen in new construction. But, I’m excited to experience the fresh air it delivers!

Insulation Time

passive house update, simplifylivelove blowing insulation

Once the plumbing, electrical, and HVAC were installed, it was time for insulation. We spent some time cleaning up and emptying the house to make room for bags and bags of insulation and the insulation blower.

passive house update, simplifylivelove - fabric on walls

Now, the crew is hard at work blowing insulation. But before they can blow the cellulose into the 17″ walls, they have to attach this fabric to the studs to hold it in. First, they staple it to the studs. Then, it has to be glued down too. This is what I mean by everything takes forever. It seems there are 17,000 steps just to get to one thing.

Blower Door Test Results

By the way, a few people {mostly geeky insulation aficionado types} asked me after my last update if we passed our blower door test. YES!!! We did pass the blower test. In a most impressive way, even. If you’re curious about the blower door test, here’s a bit of information. Many of you might be familiar with the Energy Star Certified Homes model. The most current energy code is Energy Star 3.0. To qualify for Energy Star 3.0, a house must achieve a rating of 4.0 ACH 50 on a blower door test. This test measures how much air a house leaks and locates the leaks, so the house can be tightened up.

Passive House Standards are much tighter. We needed a 0.6 ACH 50 on our blower test for our house to qualify for passive standards. To make sure we’re on the right track, we did a blower test at rough-in stage. We actually preformed this test back in December and our house rocked the test with a 0.35 ACH 50 – 40% tighter than the current PH standards, and we still have more layers of insulation to add. You can read more about blower door testing here, if you’re curious.

What’s Next?

So, now we erm they, keep blowing that insulation. Bags and bags of insulation. After the insulation is complete, it will be time for drywall. The dry wallers have been out to see the project and sent their bid. Now I just have to get my husband to accept it and move on. 😀

Next month – I will have pictures of completed insulation AND drywall that is actually hung on the walls. We’re getting there, my friends. Progress is happening!

Until next month, friends…have a great weekend!

Curious about other passive house posts? Read these:

What is a Passive House?

Passive House Update – 6 months to Move In.


Wednesday 2nd of November 2016

Your play by play description is an interesting one. Hopefully, your insulation process, once completed, was all you intended.


Monday 29th of August 2016

amazing, perfect design, I am preparing a project with isolation, but how much energy I have not decided yet, but I'm getting some ideas, thanks


Sunday 8th of March 2015

Can't wait to see the FINISHED product in June! (If all goes well next week...) ;-)

Michelle Marine

Monday 9th of March 2015

Yay!! Hope you make it out, but pretty darn certain we will ;-)

Julie Pullum

Sunday 8th of March 2015

I hadn't caught up with the house for a while and am amazed at how it's looking. The end is in sight! It's looking awesome!

Michelle Marine

Monday 9th of March 2015

Thanks, Julie. I haven't honestly shared that much about it. But the end is in sight now and there is actually progress to share. Yay!!! <3

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As an Amazon Associate Michelle Marine, SimplifyLiveLove, earns from qualifying purchases.