▱ This LGA-designed residence responds to the local challenge of building on the side of a mountain as well as the challenge to us all of providing energy efficiency. Photovoltaic panels on the roof power the water heater—not just the home's electricity. It's also super-insulated: the practice of installing more insulation than required by code. Donald Hostetler, owner of Wood Works Unlimited, Inc in Colorado Springs, was the contractor for this project and took the time to answer our questions about building the home.
▱ Have you supervised a solar water heating installation before?
No, this is my first
▱ What makes it different?
The solar panels recirculate Glycol thru the panels into a water storage tank where it then heats the water for the domestic hot water needs in the home. How does it interact with the other systems in the house? The hot water storage tank has dual coils inside of it and is also supported (as a backup) by a boiler (used as the main heating source for radiant heat in the home) in case of panel failure, shade or a unusual heavy demand of hot water (guests during the holidays, etc.).
▱ Where was the extra insulation installed?
The first step was to use the best window to minimize heat/loss/gain. We chose the Marvin wood triple pane windows in the casement style. Next we used a open cell blown foam insulation in the walls and attic areas. This foam is a heated liquid and mixed, then blown on the the wall/attic surface, within 15 seconds expanding to 300 times its liquid form to a cured dry to the touch product. It seals any and all air infiltrations to provide a very airtight envelope.
▱ Was any special material chosen?
We chose "ICYNENE LD-50" for all the foam areas in the home. The company must be licensed to buy/install this product in homes.
▱ What other high-performance elements are there in this house?
We also installed a 5500 watt PV solar system on this home that will back feed the grid at times that output is greater than demand. A whole house air exchanger to keep fresh air available into the home and condensation to minimum. We also applied for and received a "Variance" from Regional Building Dept. for a non-vented attic. This allowed us to have the foam applied on the underside of the roof sheathing and created a "conditioned attic" no more hot oven in summer and cold in winter to keep out thru the use of soffit venting. This is also a great way to keep fire from spreading up an outside wall and entering the attic space thru the soffit venting in the case of a wildfire.
▱ What was your role in recommending and advising the owner on them?
The owner wanted to take advantage of any wind or solar that may be available, wind power was not an option on this site. So the research began on my part, after careful consideration we chose the systems mentioned above.
▱ How does the site compare to other available Colorado Springs sites?
Average I would say, trees were a challenge and because it was a hillside lot had a lot of restrictions that we had to adhere to.
▱ What were the challenges and successes of building the Idler residence on this steep slope?
The biggest "challenge" was to make sure that the roof area dedicated for the solar panels took advantage of the best sun, minimum shade thru the different seasons. The success would be we actually got more watts than first thought from the PV system given the final location. Most of the rear and side of the garage is below ground level and helped redirected the drainage around the home much like a large retaining wall,it also helps keep the home from having a very tall appearance.
▱ Have you received any feedback from the owner that you can share?
Too early yet for utility comparisons, they say it is very rewarding to watch the electric meter running backwards and that the home is "very quiet from outside noise."
▱ Any other observations on this project?
I am considering making the triple pane window along with the foam a standard feature on all future projects, the performance during the construction was phenomenal, from the temp heat phase thru the final, the majority of this home was built during the winter months and had the lowest utility bills for construction of any home I've built.