From Horse Barn to Wellness Center, Part 7: Building with ICFs and Air-Source Heat Pumps

Reader Contribution by Adam D. Bearup and Hybrid Homes
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Photos by Adam D. Bearup

Following the journey to remodel a horse barn into a commercial wellness center on a Midwestern property zoned for agriculture. Thismulti-part seriesrecounts the considerations, pitfalls and ultimate successes of a green-building project with an ambitious scope to bring a defunct farm building new life as a natural health destination.

I called the owners and told them about the good news from the power company and that the price to get electricity down to the barn was going to be less than it could have been (see Part 6 for that backstory). I called the solar installer and told him what our plan was.

We created a plan where he would bring a trencher for the conduit that he had to bury and when he was on site, he would make a trench for us so that we could bury the big 200-amp service wire that went from the house down to the barn. We were all excited that we could get everything done in one trip. He would be down in a few weeks to do the trenching, so we had the time to connect with the electrician and get the big wire ordered.

The excavator had finished digging our footing and foundation trenches, so Bob and I focused on getting that work done. Before we could start working on the footings for the east and north side additions, we had to build forms to pour concrete around the corner of the existing barn foundation walls.

The structural engineer said that these large blocks of concrete would be used to prevent lift in the barn in case of a weather event. As Bob and I were building and pouring those corner forms, we kept saying that we wondered what kind of weather event that he was thinking of because they were so massive. The corners of the east and north additions also had big cubes of concrete on each corner to prevent lift in those areas. Again, we commented on how big of a storm it would take to need something so large on the corners of the buildings.

Building with Insulated Concrete Forms

After we built and poured all of the footings that we needed for the project, we began to stack the Insulated Concrete Forms (ICFs) for the frost walls of both additions. When I drew the building plans, I asked the structural engineer if it was OK to use ICFs for those frost walls. I told him the we wanted to pour our concrete slabs on top of the concrete core of the ICF and leave the exterior foam of the ICF higher to insulate the outside of the slab. He told me that it was OK to do that and that he liked that idea as a way to insulate the heated slab.

When the frost walls were poured, I called the excavator and asked him to come and backfill the frost walls so that we could pour our concrete slabs. I had to make sure to ask him to backfill everything with sand instead of the clay that was everywhere so that we could have a better chance of combating the frost during the winter time.

Taking out floors.

Considering Geothermal and Air-Source Heat Pumps

The owners and I spent a great deal of time trying to determine what heating and cooling system would be the best fit for the Wellness Center. I originally met the owners through an email that they had sent me asking my opinion on geothermal. I told them what I had thought about geothermal heating and cooling systems and then asked them if we could use the same amount of money as geothermal but to allocate it in a different way. That is when we started to talk about increasing the size of the solar array and using more electricity in the Wellness Center.

Ultimately, the owners chose a radiant heat system on both floors of the Wellness Center and to power the boiler for that heating system with propane. The thought was that the Wellness Center was going to have spray-foam insulation so the demand for heat wouldn’t be as great. This also left an option to switch the boiler to electric some day if that made sense and maybe even revisit geothermal as the heating source if the propane boiler became too expensive.

The Wellness Center needed a cooling system and also an air exchange system so we decided that combining those systems would make the most sense. In addition to the radiant-heat system, there would be two air handlers (basically furnaces but without the burners in them) that each had an air-source heat pump that would sit outside.

The air-source heat pumps would provide cooling during the warm months and also provide heat during the cold months when the temperature was within a certain range. When the weather got really cold, the air handlers would be able to provide heat by way of an electric heat element in each air handler. We chose the electric heat elements because of the large 20-kilowatt solar array that was going to be onsite.

The Wellness Center layout required us to cut doorways through the existing foundation walls. We had to use a gas powered concrete saw and sledge hammers to break through the old, hard concrete. After we had the door ways cut in, we laid down the two-inch foam board and I called the heating contractor to come out and install the tubing for the in slab radiant heat.

While we were laying the foam board down, the solar installer arrived and started trenching for the conduit for the large solar array and, as promised, he made us a trench for our 200-amp electrical service wire.

Pouring Concrete Floors

The heating contractor came out and installed the tubing for the in slab radiant-heat system. After the mechanical inspector approved the tubing, we scheduled the concrete floors to be poured.

Bob and I poured and finished the concrete slabs for the additions and we had a local concrete company do the larger floor inside of the existing barn. Bob and I poured an exposed aggregate concrete floor where the entry way of the Wellness Center would be. The owners gave us special stones to toss around in the floor and we were excited to see how great they looked as we washed off the top layer of concrete to expose the stones.

After the concrete floors set up, we started to build the first-floor walls of the east addition. This addition was exactly the same width as the posts that held the roof that we had removed. This was one of the stipulations from the township, that we had to build within the existing footprint of existing barn.

Replacing the Barn Roof

We were following the same plan that I had told the structural engineer: Build the main floor walls, set the floor joists and subfloor, build the second floor walls, and then remove the east side of the existing barn roof. We had to remove that section of roof so that we could create a large open area between the existing hay loft and the upper floor of the addition.

We always keep an open mind as we approach work that we have not done before. Removing the barn roof was going to take a process that we hadn’t figured out yet. We had an idea of what we wanted to do and changed that approach after we looked at the details that I had drawn and thought about the way the barn roof was supported.

We decided to build and secure the new roof system to the old roof system using the details that the engineer had described to me. We did this so that we were absolutely sure that the roof system was supported and safe. After we finished connecting everything together, we cut out the east roof of the existing barn.

One by one, we removed the lower portions of the barn roof trusses and as each board came out, our confidence increased.

Bump in the Road for Solar

As a favor to the solar installer, I contacted the building inspector to let him know that the solar installer would be submitting a building permit for a solar array at some point in the next few weeks.

The building inspector said that solar arrays were not allowed in the township. I asked him if he was joking, because I had passed a roof-mounted solar array that morning on the way to the jobsite. He said that he wasn’t joking and that roof-mounted solar arrays were OK but that the Township did not allow ground-mounted solar arrays. He suggested that I call the Zoning Administrator for clarification. I called the owners and let them know the news — they were noticeably frustrated, as was I.

Follow the full series as the saga of the horse barn to wellness center transformation unfolds.

Adam D. Bearup is a designer, green builder and farmer, who learned about biodynamic and regenerative farming for a project he built in Northern Michigan, The Earth Shelter Project MichiganAdam has degrees in marketing and management and a Masters of Science in Green Building. Read all of his MOTHER EARTH NEWS posts here.

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