Our lot actually has things growing on it. But not a house, yet. Time for an update. Long story short, it took a long time for our builder to get quotes from subcontractors. When he finally got us an estimate, the cost was significantly higher than we had ever anticipated. At that price, the project was not within our budget, and didn’t make sense. We’ve decided that the way forward is to significantly reduce the size of the project, as well as simplify where we can.

The project is back on track: Plans are final, engineering has been done. We have a signed agreement with our builder. The builder is excited to work on a project that’s a bit different. Cost estimates are still high, but no longer completely out of reach. Timeline is still in flux, but building might start in a few weeks! Floor plan changes The floor plan was pretty close in September, but even so, it could be optimized quite a bit.

Windows are a balancing act between light, views, insulation, heat gain, and of course cost. Passive house windows need to be triple-pane, their frames need to insulate well, and they need to seal tightly, so they will necessarily cost more than regular windows. Detailed quotes We got quotes from multiple vendors, and made a lot of changes in response to those quotes, optimizing number, size, and type of windows. To do that, we needed detailed quotes listing the cost for each window, instead of just giving us one (very large) number.

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.