Our builder has said a few times “You’ll be able to heat your ADU with a candle.” The concept of that is pretty alluring, though perhaps a little far fetched (I’ll be sure to test it out). Either way, insulation has gone in and the space seems like it’s going to be pretty nice.

The first step was 3″ of spray foam insulation in the ceiling. This not only provides about R20 in the ceiling but also sealed all air gaps.

After the spray foam, additional insulation was blown into the ceiling cavities, creating a total of over R35 in the ceiling. You can see the worker on the left blowing in the loose insulation behind the sheer material. Above the worker on the right you can see the sprayed insulation.

Here’s the finished ceiling insulation. Drywall will be next.

The following work day, they came back and installed the wall insulation. They cranked out this step in just a few hours. Small areas and electrical junction boxes were given a shot of spray foam to insulate behind. They also ran a bead of caulking around the sill plate to stop leaky airflow from between the outside and inside.



Getting the siding on was a major visual milestone for us! It’s so wonderful to see the ADU take shape on the outside and discover the little details that help make our space unique.

Here’s the south side going up. Notice the furring strips that the siding is nailed into. This, as detailed in an earlier post, creates a “rain screen” for moisture to run down incase water gets behind the siding.

Cedar shingles on each gable end.

The front is looking so great! Imagine this with our future glass doors letting even more light into the space. We are considering moving the arbor up 4 or 5 inches, as we didn’t foresee the arbor supports (corbels) interfering with the doors swinging all the way open. Currently they can only swing 90 degrees open before hitting the corbel. Chalk that up to “things you don’t considering while looking at the plans”.

Finally, pretty excited to see some child labor happening on site!

Electrical & Plumbing

I have a new understanding and respect for plumbers and electricians, especially the guys working on our small house. It’s a tight fit to get everything running through the walls, avoiding obstacles and maintaining the correct slope. Fingers crossed that when we flip a light switch that the shower doesn’t turn on!

It was also interesting to learn about what’s up to code. For example, wall outlets need to be placed every 12′. We’ve been living in a house built in 1926 and we’re lucky to have maybe two outlets PER ROOM.

Electrical and plumbing under the kitchen window.

IMG_9302.JPGJust some of the wires running for the bathroom. The yellow wire in the upper left runs to a small electric space heater for the bathroom.

IMG_9317.JPGWe had to get a new double power meter on the side of our house and it’s a little ridiculous how big this thing is. Notice the large feeder wire heading into our basement through the hole in the exterior wall.

Exterior Building Science

To create a little slightly more spacious interior we are using 2×4 stud walls, though 2×6 seems to be more common these days. One of the advantages of the thicker 2×6 wall is the ability to stuff more insulation into that thicker cavity. So, to help bring 2×4 walls up to insulation code, our ADU will have an additional 1″ ridged foam insulation on the outside as well. Not only will this bring up the overall R-Value, but it helps to create a “tighter” space, meaning there are fewer spaces for drafty air in the walls.

R Max is the 1″ ridged insulation over the entire exterior

Over this insulation is laid the vapor water barrier, which as expected, helps control the moisture that can penetrate the exterior.

Yellow water barrier

The next layer will be the .5″ rain screen furring strips, which are essentially thin slats of wood spaced 16″ on center to which the actual siding will be nailed. The furring strips create a small airspace between the siding and the weather barrier, which if any water does get behind the siding, it will flow down and out.

The firewall side of the ADU gets its own special first layer before all the other exterior materials: sheetrock. This helps reduce the ability of fire to spread from inside to out (or vise versa) and is required by code.

Mini Split Puzzle

Determining the indoor location of the mini split proved to be one of the biggest challenges to date. The plans called for the indoor blower to be up in the loft, next to the bed, but the reality of that location was less than ideal. Not only would the heating and cooling blow down onto people sleeping only a foot away, but the conditioned air would have a lot of structural obstacles to move around to get to the lower level. Other wall locations were not viable because of the firewall, while another location was unsightly.

We finally, finally determined the best location and we’re really happy about it. It’s high enough to heat and cool the entire ADU, yet the indoor unit is tucked away. The extra bonus was the ability to run the refrigerant lines along the underside of the exterior eave, which will be enclosed and never seen.

To be honest, the mini split is one of the things I’m most excited about – modern and efficient heating and cooling!

Indoor blower location.

Refrigerant lines running in the eave.

Framing: Day 2 & 3

Well, that was fast! It didn’t take long for the framers to knock it out and seeing the framed out ADU now is really exciting and impressive. There are a few areas that the framers need to address still, hopefully soon, but we are moving along. All the rain we have been having makes us even more anxious to get the roof shingles on and the windows in place.

IMG_8944.JPGThe first roof joists.


IMG_8970.JPGThe ridge beam was dropped into place with a crane.

IMG_8975.JPGGetting there.




Framing: Day 1

Framing goes fast.

Five guys cranked out framing from about 8am to 4pm and they made a ton of progress. This is our first opportunity to see what we’ve only looked at on paper to come into the 3D world. It’s so exciting. Some impressions so far:

  • The size of the ADU in the backyard feels about right, a little more encroaching than the old garage, but that’s expected
  • The lofted ceiling is going to be awesome.
  • The bathroom is small, or let’s call in “intimate”

A few snags from today:

  • The framers built the little bathroom wall between the shower and toilet, based on the plans. That was an easy fix for them to remove.
  • The black metal hanger brackets we wanted didn’t make it into the materials order. The GC is scrambling to source those asap.
  • The spacing of the four front upper windows was awkward and not how it looked on the plans (good catch Leighann). We caught that in time to have them adjust the spacing to be equal across the top.
  • Bathroom sink plumbing and supply lines come up out of the floor rather than out of the wall. This is a way bigger deal and we need to address this with the GC. We’re not sure why, one theory is the North wall of the ADU is “fire rated” and that changes the building in that area? Bathroom vanities all have utilities coming out of the wall, so we have some problem solving to do.

Some photos from today:




Reclaimed Fir Window Sills

A couple of years ago Chris gave us a big stack of old doug fir 2x4s that came out of his 1920s house during a major remodel. I knew these would be good to have, though I wasn’t sure at the time how we would use them. They sat partially covered in the old garage, collecting dust and mouse poop. Invading hop vines became tangled and intwined around the lumber, they sat weathering the seasons.

When it came time to seriously clear out the garage in preparation for demolition, we had to move the lumber again, and I began to wonder if they were more of a burden than an asset. Constantly shifting a stack of wood is no small undertaking. We moved them outside, to really the only place we could find, and wrapped the pile in a tarp to keep out the elements. Despite the rainiest February on record (11″+) and Portland Snowpocalypse 2017, the lumber sat, protected from it all.

During that time we became inspired to reuse they timber in the ADU as our future window sills. The thought of these almost 100 year old 2x4s adding a warm, natural glow to our space really got us excited, as of course did the opportunity to recycle perfectly good material that could have otherwise been tossed.

But how would these weathered, rough 2x4s look with a little love?


I contacted Creative Woodworking NW and scheduled a time to bring the wood down to their industrial shop in SE Portland. The offer “shop time” with one of the staff and for an hourly rate they work with the wood to turn it into what you want. Here’s the process:

Running two sides through the jointer machine.

Gluing up the 2x4s to create the desired depth of the window sill.

Additional sanding and planing the next day after the glue had dried. We did this to get the  wood down to 1″ thick.

The rough cut finished product! It still shocks me to see the rough, worn wood literally be stripped away to reveal the beautiful core. There are few still blemishes, mainly nail holes, but I feel that’s a wonderful reminder of where this wood came from, it’s long history, and how we recycled and repurposed the timber. Can’t wait to see these sills installed in a few months.