Air Tight

We had our blower door test about a month ago.  It's pretty cool.  Nathan agreed to write this post...and with that, here he is!  I'll add the photos & exact cfm's in later!

After getting all the windows and doors installed, sealed and caulked tight, it was time to call for the "blower door test".  Kristen has mentioned our goal of building a high performance house, and stopping drafts and accidental air leaks (aka: "infiltration" in architect speak) is a critical component of our  overall design. 

For the test, we set up the blower door tent over our front entryway

, sealed that up tight and cranked up the fan- sucking air out of the house until we had established the industry standard pressure of 50 pascals. Note: to achieve this kind of pressure differential naturally, I've been told that you'd have to have around 50mph winds blowing against your house. [Kristen here, the blower door testing guy told us this...]
We had really good results-  with 922 cfm of airflow initially.  We walked around the inside of the house and tried to locate any places where I had missed caulking and sealing the sheathing and windows when I was getting the walls framed up and closed in.  Surprisingly, a couple of our doors were not locked, and as soon as we did that, they sealed up tighter and we had an even better reading on the fan with 897 cfm.

Our goal of reaching "Passive House" standards translates that cfm into total air changes per hour.  The target is 0.6 ACH (Air Changes per Hour), and at the time of this first test, we had hit 1.4 ACH.  I'll attach some links for you all to look at if you are interested, but for reference, current code minimum is 7.0 ACH and "energy star" minimums are at around 6.0 ACH. 

We might not get down to that German "passive haus" standard, but we'll keep improving.  I'll do another blower door test after we get up the sheetrock, and once more after we get the rigid insulation, stucco and siding installed in the summer.

"WINDOOOOWS! AWESOME!"

J said it best as we drove up to the house today...."WINDOOOWS!  AWESOME!  THEY ARE BOOTIFUL"

I have to admit, I was teary eyed as I came around the corner and saw a warm light coming through the beautiful windows!  I love the green we chose.  It feels so full of life while the earth is so brown right now.

K & T's from the West side

Terese came over to check out the windows.  All the windows on their side were installed today.  We had the bounty of having the Marvin guys come over this afternoon and show Nathan how to do the intall.  It also helped to have a few extra hands to install the largest of the windows.

Terese and I were able to help Nathan install the last of the windows.  The double window in Terese's study.  We didn't know that we would be helping, but we were both excited to do it!



At 27°F when we came over, it was a cold but productive day.  J and I brought over a warm cupa to enjoy while looking out the new windows!

J and Nathan taking a load off



K & T's from the east side

The Roof is Done!

Nathan worked a bit later than usual tonight because he was ALMOST DONE with the roof.  He had his head lamp on and was putting up the last of the drip edge.

What does this mean?  Tomorrow he can sleep in and rest easy as the winds pick up and we're supposed to get dumped with snow this weekend.

Roof is on!!

J and I got over there just before it got really dark so we could snap a picture and be able to yell in the street like crazy people! :)  Needless to say, it's been a much anticipated day!

Roof Coma

The treatment for Roof Coma is to veg out!  J was happy to assist.  She's watching her movie, he's watching his movie.  Mom is knitting.  Yea!

Super Insulated House

"Oh MY!  It's such a big house!"  is something we're hearing quite a bit now.  I want to explain partly why this house looks big:

First of all, the house is designed as two separate living spaces, but with some flexibility for overlap when we want it for big family events like Thanksgiving or birthday parties.  As a whole though, at about 3000 square feet, and providing housing for 5 people (Terese, Keith, Kristen, Jocelyn & Nathan) we all work with about 600 square feet each- down to 500 if we have another kid some day- so we are way below american norms of recent decades. Check out this article on sq ft per person for mor on that: http://www.100khouse.com/2008/10/20/so-many-square-feet-so-few-people/

Note:  we'd be down to 448 square feet each if we end up have in-home nursing care for "nona & papa" some day...

A second issue is that we decided early on to spend our money going up, not down.  With no basement (just a crawlspace) our square footage is all above ground, making our house fit in scale with some of the biggest houses down the street, but actually being a bit smaller from a real-estate perspective...

We also have an issue with "goss" square footage (based on outside dimentions) and "net" square footage  (based on usabe interior dimensions- excludes wall thickness). Anyone that knows Keith or Nathan knows that 'building a house' isn't going to be a "normal" house.  One of the things about our new house that was not discussed very much up front, was the insultation quantity.  We all knew the house was going to be super insulated.  There were no objections! 

Nathan often talks about his dislike for houses that are built in a way that they are cold in the winter and warm in the summer...instead of warm in the winter & cool in the summer.  Well, do have a house that does this, it requires much more insulation than a 'regular' house.

A code minumum house has an R-19 wall.  Most construction projects don't go above this value.  If you want to know more about R-Values you can geek out a bit here.  Our wall insulation when we're done will be at R-50.  When the interior walls are built, the thickness from the outside wall to the inside wall will be 12 inches.  This gives us quite a bit of space to fill up the void from the outside to the inside framing with insulation. 

To give you an idea of the difference this makes, here are some numbers for you.

(The gross is the outside footprint of the house)
The gross square footage of the main floor is 1897 sq/ft
The gross square footage of the second floor is 1339 sq/ft

(The net is the inside, usable space of the house)
The net square footage of the main floor is 1580 sq/t
The net square footage of the second floor is 1080 sq/ft

That's a 24% difference between outside & inside square footage.  All buildings have a difference between the gross and the net footage.  They are not usually THAT different.

This isn't a common practice (yet) to build a super insulated house becuase of the extra materials cost.  Inside framing materials and double the insulation price.  When you are looking at your house building budget and you see a value that *could be cut in half, it's pretty tempting to go ahead and do that. 

We decided not to.

In order to compliment our super insualted walls we went with the best quality an R-Value windows and doors we could find.  Any hole (window) we punch through the envelope of the house is energy we are loosing.  We want natural light without having to give up

1. The charm & beauty of a the window (We decided we didn't want to do a basement because we value the light so much)

2. Energy efficiency of the structure.

3. Meets code & egress requirements.

We did order another window to view it before making a final decision.  The window did not end up meeting the code requirements for egress, even though that was one of the specifications of the window when we bought it.  We returned it.

We did go with Marvin Windows.  They are not paying me to say this!  Quite the contrary, in fact! :)  They are made in America, Minnesota to be exact.  They are triple paned.  They are easy to clean.  They have aluminum cladding (we're not fans of the vinyl cladding), Wood structure (other windows we looked at were torqueing - the window wasn't staying plumb! Yikes!). We don't have to comprise on beauty and detail to get this window!

We put in some mullion details that make it fit into the older neighborhood nicely.  They have a screen option that allows one to look out the window and not see the screen and the window doesn't look darker when looking at the house.  This is important becuase although we want the windows to look like they are all functional, we have some that are functional in the same bay as windows that are not functional.  Plus, it's really cool to look out the window and not have the mesh of the screen keep catching your eye!

We treated our big patio door as a window.  The door company patio doors couldn't come close to the R value that the Marvin door had. 

patio doors

Remember how big that sucker was?!  We wanted to have the view, the flow and versatility this door would give us in the floor plan, but we didn't want it to be negating all energy perfomance we are trying to obtain.

I think we found the sweet spot with Marvin.  Doable in the winter?  Yes.  Dinner parties that can spill out onto the patio garden? Why, yes, you can have that too.

I think I have Marvin's link at the bottom of the page.  If not and you want to know more, Karen at Billings Window and Door is awesome!