We all have been feeling the pocketbooks getting lighter at the gas pumps. Homeowners have also noticed less money at the end of the month with continual increases in natural gas, L.P. gas, water and power.
Kevin Nash from the U.K. and Kris Doll from Onslow, Iowa, came to my company, Advanced Designs LLC, seeking a solution to today’s extreme energy costs. They wanted to build a home on a beautiful 40-acre site with a four-acre pond just north of Onslow, in Jones County. Nash suggested building a cordwood home heated by a wood stove, since they are popular in the U.K.
To be honest, once I explored this route I thought Nash was crazy. After looking at it harder, he realized the benefits just weren’t there. The biggest issue he had was finding someone to build a wood/mortar wall system. The wall would be 24 inches thick and required a post/timber frame for structural stability. Doors and windows were going to be an issue, as well as care, maintenance, insect and pest issues, moisture and air infiltration, rot and mildew—all that headache for a mid 20 R-value wall? It didn’t really make sense.
Kevin and Kris also required the property and home be off the electrical grid and not require any piped-in energy. We decided the best approach for a zero energy home (ZEH) was an ICF home. In our design both the wall and floor systems are ICF and we created a very efficient passive solar gain design in a three story, completely self sustaining home.
The project has been very challenging, both in designing and in building. The site required a nearly 1/2-mile-long drive with some steep grades. The drive had to be strong enough to handle the construction traffic ranging from pickup trucks to 30-ton concrete pumping trucks. The soil conditions were not the greatest, so our excavator, Kevin Arensdorf Excavation, Anamosa, Iowa, handled this situation with great care.
Once we had the drive and water well installed, we started building the home, but only after going through a number of subcontractors and suppliers that were terrified of taking on this project. It seems that when someone steps out of their comfort range, meaning what they have been doing repeatedly, several hundred times over the years, they get scared. We finally assembled a small group that was open to the unique project and willing to make this project a reality.
We first teamed up with the best ICF installer we have ever come across in Iowa and Illinois, including Chicagoland: Johannes Construction, Earlville, Iowa. Because this home is all concrete, with the exception of the roof, we wanted to make sure we had the best ICF installer. Even though the home is simple in footprint; we had a considerable amount of steel and concrete to place.
All the walls are built from an ICF wall system. They are 6.25 inches in thickness and boast an installed R-value of 25, but they should perform much higher. The homeowners were impressed with the system’s resistance to rot and decay, fire, insects, its high STC rating of 50 for sound transmission, and that it can withstand some very high winds. The ICF flooring system (Lite-Deck) is 16 inches thick with a 4-inch topping, making it 20 inches thick, clear spanning 30 feet.
We felt that it was important to install a backup heating system. As a third generation home designer/builder in Iowa, we know the sun sometimes decides not to poke its head out for days or even weeks at a time here in Iowa. Winter can get very brutal here with the wind and cold. It just made sense to have a backup system. So inside the home, we had a radiant floor heating system installed by Comfort Solutions, Springville, Iowa, which serves as a backup to the passive solar system. Each room will have its own zoning controls.
Comfort Solutions will also install an A/C system with ventilation and air exchanger. We chose a high velocity system that really lends itself well to this type of construction.
In this day and age, you certainly can’t live without power. In order to be off the grid we decided we would produce our own power by means of wind and solar, with a backup gas generator. Right off the bat, we installed a 3000 watt per hour wind generator (Whisper 500). This will charge the battery system in the house, which will supply power to the entire house and all of its systems. In the next year or two we will install solar collectors for energy production. The home will use mostly low voltage systems with LED lighting for maximum efficiency.
With Iowa being the unpredictable beat that it is, I insisted on having an 8.5 kw L.P. powered backup generator (Kohler Guardian). This system will ensure that Kevin and Kris will always have power to their home to cook, dry clothes and for a backup heating system. L.P. gas makes sense; it is reliable and reduces our electrical demand on the system.
The performance of this house is impressive. The energy calculations show projected demand if the home were 100% dependent on backup systems for the entire year, so of course these numbers will be considerably lower in reality. We wanted to show what worse case scenario was for this home since it is completely off the electrical grid. Our choice of other building components was based on the type of high performance they would provide. We are installing tight doors and casements windows. These are some of the best 3/8 inch insulated tempered glass windows, with blinds between the glass, Low-E coating, and they are argon filled. The U-factor on these windows is .25 with a solar heat gain coefficient of .15—very good performance for the money.
Our roofing system will be an 11 7/8 inch joist filled with insulation. This will give us an R-80 range for our roofing system. This is critical because most of the heat loss is from the ceiling. Just using this system will save us up to 50% of heating energy. On top of this roof framing will be a light colored metal roof. This type of roof covering provides low heat transfer with great reflective qualities while withstanding the ravages of Mother Nature.
Our garage is the only wood framed structure on the home, other than the roof. The garage will be located on the north face of the home, made from 2x6 studs, with insulation (Icynene Insulation System) in both the walls and ceiling, which will provide a great wind break and thermal transition from the cold winds in the wintertime. The garage will be heated as well, and both the garage and the lower level slabs have 2 inches of high density rigid insulation under the floors.
We have made careful consideration to thermal breaks of all building systems that come into contact with the outside environment. All windows and doors and other service penetrations will all have some type of thermal break installed to eliminate any heated or cooled air leaking or transferring to the outside world.
We will finish the exterior with stucco, and install aluminum fascia, soffit and gutters to the home, as typical. We have large overhangs on the south face to prevent sunlight flooding inside during the cooling season. However, during the heating season, the sun will be low enough to miss our overhangs and allow the sun to heat our tiled floors over our concrete flooring system. This will provide a nice thermal mass and will store this energy very nicely.
The owners have some great plans for this property: they plan on growing organic crops, including with a wonderful vineyard. They have also entertained the idea of a bed-and-breakfast on this property. They are planning on building several smaller cabins along the lake. Future plans also include teaching people how to cook with wine and organic foods. They also want to show homeowners about renewable energy sources and concepts.
Advanced Designs LLC has been designing and building homes that are innovative, unique and highly efficient, and that are affordable, for many years now. We feel that the ICF system is the next logical evolution in the building trades. With the ever increasing demand for the world’s crude oil and other energy resources, we will continue to see alarming price increases for these crude oil based products and services. All the consumer can do is complain and pay out the nose for it, unless, of course, they build a ZEH house. I think Kevin and Kris are ahead of the game here. I think this type of home is a very wise decision on their part.
Kevin and Kris welcome anyone who would like to come and visit their home and see first hand what a ZEH ICF home is all about.