Shelving Rock – Multi-generational highly efficient living made possible through ICFs
By Vanessa Salvia
When the complexity and craftsmanship, architecture, sustainability and other factors in the judging rubric were all sorted out, there was a clear winner in the 2017 ICF Builder Awards for the large residential category.
The home known as Shelving Rock, in Glenville, New York, won Large Residential – Best in Class, announced at World of Concrete in Las Vegas in January 2017. Large residential covers homes in the 3,000 to 6,000 square feet range.
Shelving Rock definitely qualifies as a “large” home. “The overall square footage of the house was 3,480 on the main floor and an 80-square-foot bonus room above the garage and a full basement for a total of 4,280 square feet,” says Andy Ellis. His company, Halfmoon Construction Co., undertook the job as both general contractor and ICF installer. Ellis uses Logix ICF exclusively. “The house had 30 corners inside and outside and 16 of them were 45-degree angles, so it was a very complex design.” The home was designed by New York architect Eric Vickerson, who typically designs commercial buildings.

Photos courtesy of Halfmoon Construction Co.
But when your company only builds two to three homes a year, why not make those homes spectacular? This is Halfmoon Construction’s sixth full build using ICFs, although before that he completed other projects using ICFs for a portion of the build, such as foundations, with stick-built above that. Ellis founded the company in 1999, and in 2013, Ellis had a customer request a zero energy home.
“He said he wanted to be able to pull the meter off the house and I said, ‘Oh boy, do I have a great product for you!'” Ellis recalls. “I told him that with ICFs zero energy could be really easy. Since that house in 2013 I have not built any other type of house.”
Now, everyone that comes to Ellis for a home wants an ICF home. “I usually don’t have to convert them,” he says. “Anybody that comes to me knows that I do ICF. I may have to talk to them about it so they understand what they do, but it doesn’t take a lot of convincing.”
Most of the time, Ellis says, his customers want energy efficiency. “I go through the benefits of how healthy it is to live in an ICF home and how their energy use is going to change and most of the time that’s what they want.”
Universally accessible
And while it is a large home, it was also meant to be home for three generations of one family. “The main floor was multi-generational living,” Ellis explains, “so it had a 780 square-foot mother-in-law suite with a full ensuite and entire kitchen. She had a bedroom, living room and her own bathroom so that was one of the really cool things about it. The three generations are living together with Grandma in her own apartment, basically.”
With Grandma there and the other two generations expecting to be in the home for the long-term, the whole house was designed around universal design principles. These principles are meant to ensure that a building is accessible to all people, young and old, with or without disabilities, throughout their lifetimes.
Hallways are 4 feet wide and every door in the house is 36 inches, to accommodate wheelchairs. Most of the entryways used pocket doors, including closet doors, which means that there are no thresholds and no doorknobs or handles. The shower has no threshold to step over. Ingeniously, the front door has a Kevo lock system. “It recognizes your cell phone and it will talk to you,” says Ellis. “As you approach the door it will unlock, so if you’re in a wheelchair or your hands are full it unlocks for you.”
Surrounding the kitchen island is 36 inches of clearance. In the island is a drawer-style microwave. “It’s really cool,” Ellis explains. “You press a button and it automatically comes out and opens. You put the food in and it closes again. There’s no reaching around or above the cabinet to get the food in there.”
All the vanities throughout the house were designed so that their centers could be removed, for wheelchair access if that is ever necessary. “We talked about accessibility,” says Ellis. “The house already had 4-foot hallways and I talked with them about increasing the size of a couple doors in the house for access. We did talk about increasing the door space so it was 100 percent accessible.”
Extreme energy efficiency
With nearly 7,000 square feet of conditioned space in this house, though, you might expect it to be an energy hog. That’s where the magic of ICF and the thoughtful sustainable touches they put into their design really paid off.
The home has an Aztech Geothermal Heating and Cooling system installed, and it turns out the building site was optimal for that energy source. They used a ground source horizontal system consisting of five loops at about 100 feet long for each loop. Geothermal systems are typically vertical loops, but horizontals loops also work. There’s no drilling necessary for horizontal loop installation. In this system, the water runs through the loops and captures the heat from the ground.
“Our BTUs of heating per square foot of heating were about 6 per square foot,” remarks Ellis. “I know the industry average from geothermal heat pumps right now is about 32 to 35 BTUs per square foot, so we’re at a fifth of what our standard homes are today.”
The home’s name, Shelving Rock, comes from the geological feature of a large base of shale on the site. “There was a lot of natural water coming across the shale,” he says. “We went down almost to bedrock, and there was a constant replenishment of 55-degree water, which made for ideal conditions for geothermal,” Ellis says. “We were able to very efficiently heat and cool the house by running the heat and thermal loops right on the shale.”
An advanced wastewater treatment system by Norweco reduced the size of the septic leach field by 30 percent. The system breaks down waste over a three-component system. By the time the wastewater reaches the third component it is non-potable reusable water that can be used to wash a car or irrigate the lawn.
No special engineering required
This home did not require any special engineering. Ellis used a 6 1/4-inch ICF wall, with no stick framing anywhere in the home. There was no need to use steel headers in the garage, across doors or around windows.
In fact, with the 30 corners of the home and many of them 45-degree corners, the ICF actually made that easier to do. Most of the walls from footing to roof were 19 feet.
Ellis used the Logix standard block, which has an R-value of 24. The roof ended up being R-60. “We sprayed in 2 inches of closed cell foam and we laid in 12 inches of blown-in cellulose on top,” he says. Closed cell foam is a rigid insulating material that can increase a home’s insulation by up to 50 percent better than traditional insulation methods.
Logix for the win
Ellis says he’s always relied on Logix for his ICF builds because of the service he gets from his dealer representative, Curtis Lumber, and consistency of the blocks. “When we’re going from a corner to a standard straight block, the webs all line up the way they’re supposed to. When they’re 8-inch on center, the webbing lines up, and I really like the polypropylene webbing they have.”
Ellis goes on to explain that there’s an indentation for the rebar to stick into a spot where there’s a high-strength polyresin. “If you drive a screw into that web like you would do for drywall and you try to pull that back out, you’re probably going to break that hammer claw before you pull the screw back out,” he says. “And they’re very consistent from die to die.”
Ellis appreciates that Curtis Lumber ships the ICF to him directly. “My ICF rep from Logix is named Win,” he says. “Win calls it in to Curtis Lumber and they do a PO and they bill me. That’s it.”
There were some challenges, but ICF came through
Ellis had a very tight schedule for this build. The house was listed in the Capital Region Parade of Homes to be shown on June 4. “We broke ground to the day six months before, on December 4,” Ellis recalls. “So we had to do this house from start to finish and it had to be move in ready in six months. We didn’t even start pouring concrete until the middle of January.”
In most other builds, January weather would mean no concrete pours were possible, but ICFs make nice weather not necessary. “The warmest day that we had was like 17 degrees,” he says, “so the ICF allowed us to build all winter long. There’s no way we would have been able to pour a conventional wall system with teardown panels. When I do the ICF we cap off the top of the pour with a little bit of insulation. Two days later with the chemical reaction that’s going on as the concrete is doing its thing, it’s like, 70 degrees inside the ICF form. No matter the temperature outside, it is curing the way it’s supposed to inside the ICF. We poured concrete down to about 10 degrees.”
Clean indoor air
The house earned a HERS rating of 33, even with two kitchens, three bedrooms and 3 1/2 baths. It also achieved an EPA clean indoor air certificate and is considered Net Zero ready.
One of the products contributing to the home’s clean air is interior walls finished with American Clay, a natural plaster product. “American Clay helps absorb toxins in the house and it also has the character of being able to take on moisture,” explains Ellis. “We like to use it in the bathrooms and cooking areas. Here we used it on a couple walls to help absorb moisture. When the house gets arid it releases some of that moisture back into the house.”
American Clay is available in a stucco look, which was used on Shelving Rock, or a porcelain look. “It’s very easy to install and there’s no drywall sanding so you’re not getting that drywall dust in the air,” Ellis says.
Colorhouse brand house paint has no VOCs and is so clean it’s “almost edible,” says Ellis.
Building ICF homes like this means that the home’s envelope is “super tight,” and the last thing a responsible builder like Ellis wants to do is have his homeowners stuffing the house full of toxic paint and furniture once they move in. They used local wood to finish all cabinetry and the flooring and other surfaces had no VOCs or toxins. The basement floor was plain poured concrete. The remaining flooring in the home was hickory and tile
After testing, Shelving Rock showed .7 air exchanges per hour at 50 pascals of pressure. The passive standard is .6 at 50 pascals. “We got .7, with the basement, over 7,000 square feet of conditioned space in this house between the two floors. That’s a pretty incredible number and very difficult to achieve. You could never get that unless you were doing an ICF home.”
Project Statistics
Location: Glenville, New York
Size: 4,280 square feet
ICF Use: 8, 170 square feet
Cost: $840,000
Total Construction Time: 30 weeks
ICF Installation Time: 60 days
ICF System: Logix Pro; logixicf.com
General Contractor and ICF Installer: Andy Ellis, Halfmoon Construction Company, Clifton Park, New York; halfmoonconstruction.net
Form Distributor: Curtis Lumber
Architect: Eric J. Vickerson, Niskayuna, New York
Home details:
• Home has 30 corners, half are 45 degrees
• Net Zero ready
• Mets Universal Design guidelines
• Winter build with below-freezing pour days
This article appeared in our May 2017 edition.