The original plans put the house at the minimum setback from the front (25 ft). We needed to do that because the house was bigger and we had limited space in the northwest corner of the lot. With the smaller design, we gained a lot more flexibility on where to place the house. We decided to move it 5 ft back from the setback line (30 ft instead of the minimum 25 ft).

Yesterday, we went shopping for appliances. Found some we liked, all with good Energy Star ratings, so we thought they would be fine. Today, I looked at the energy use of the fridge, and now everything is in question, as we re-evaluate water heater and solar panels. Let me back up a bit. Solar panels Solar panels are great, and we had planned to add them. However, the electricity in Kanab is too cheap, and the cost of solar is still dropping, so when we ran the numbers, it makes more sense to add those in a few years.

Our house is making progress: the architectural committee of the HOA has accepted the design, Kanab has granted us a building permit, and the walls are in the container. You read that right. We’re using load-bearing straw panels by EcoCocon: the compressed straw and load-bearing wood frames provide excellent insulation with no thermal bridges. The 100 panels are custom made for our house: The panels are 40 cm (15"3/4) thick, providing an R value of 39.

I had planned to have the house certified by both PHI and PHIUS. For PHI, we’ve already done a lot of the work using the PHPP spreadsheet, and for PHIUS, we could use the simplified prescriptive path for certification. A lot of the necessary documentation, blower door test, etc., would be shared, and the PHIUS certification would help us qualify for some tax rebates. However, while our house is simple enough for the PHIUS prescriptive path, it has too many windows.

Remember back when I discussed the lot and mentioned that clay soil was a common problem in Kanab? We were glad to know that our lot had already been over-excavated and prepared such that we didn’t have to worry about clay. Well, while digging the trenches for the stem walls, they found clay in one corner. Not good. Clearly, something went wrong while preparing the lot, and the company who did that work will be back to fix their mistake.

All houses need a strong foundation, but that’s not enough for a passive house. The whole envelope of the house needs to be insulated, and the foundation needs to do its part in keeping the heat in (or out). Here’s a basic diagram of a slab foundation, with footings under the outside walls as well as the interior load-bearing walls. Without any insulation, heat will escape through the concrete slab.

Finally – our lot now has something other than dirt and a porta-potty: the concrete footings around the house have been poured! It took some steps to get there. After the clay had been removed, that big hole had to be filled with good dirt, compacting it along the way. And some of the trenches had to be dug again. Road base was added in the trenches, then compacted, to give a solid base for the footings.

The foundation has made significant progress. The rough plumbing was put in. Then those trenches were covered back up. New trenches were dug for the interior footings. The forms for pouring the stem wall were completed. And now stem wall and interior footings have been poured. Note the cutouts in the stem wall where the doors are going to be, leaving room to add insulation below the doors (using purenit or equivalent).

The insulated foundation looks clean and simple on paper: 4 inches of insulation everywhere around the slab, making sure there’s no way for heat to escape from the concrete slab to either ground or stem wall without going through at least 4 inches of insulation. (That amount of insulation provides an R-value of about 20; 4 inches of concrete has an R-value of less than 1.) When I arrived to check on the work in progress, the reality was not quite as simple, and would definitely not insulate as required.

The slab was poured on Monday July 15, starting at 7 am. The whole operation went very smoothly. They were careful to push the insulation into place as the concrete was poured, to avoid the concrete flowing into cracks. Moving the house a few feet westward paid off: the ready mix truck could get through on the east side and deliver concrete from the back, eliminating the extra cost of pumping the concrete.