The finished home

Here are some photos of the Zero Energy Ready Home.  Once the weather warms up a bit more we’ll paint the front porch columns white and install the landscaping.

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Note the 24 inch overhangs to keep water away from the foundation.  The stone beds under the eaves hide a french drain system that diverts water to the backyard area.  This also eliminates the need for gutters, which means less maintenance for the owners.  Also notice the slightly inclined sidewalk and roll-in entry door to make the home friendly to those with disabilities.  Both the front and back doors on the home have this feature.

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The view when you enter the home shows the open layout, where the kitchen, dining area, and living room blend as one space.  This is a blank canvas for the homeowners to create a place for their family with lots of natural light.  The flooring is a vinyl plank floor that is easily cleaned and does not off-gas chemical odors.

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The cabinetry and counter tops for the home were built by inmates at a prison facility in Ionia, Michigan.  This “Prison Build” program provides job training for inmates nearing the end of their sentences, and helps provide Habitat with affordable, high quality cabinetry.  All of the cabinet boxes are plywood, not particleboard, and all stains and finishes are water-based, ensuring no toxic compounds enter the air of the home.

The appliances were provided by Whirlpool’s gift in kind program.  Whirlpool donates a refrigerator and range for every Habitat home built in the U.S.

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A look at the entrances to the laundry room and bath, and the three bedrooms.  We paint all walls, ceilings, and trim with a high quality low-VOC primer and paint.  The homeowners can add color if they wish once they move in.

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The bath cabinets and counter, also made by the Prison Build program.  The bathroom of this home is large enough to have a five foot diameter turning circle for a wheelchair, and although accessibility features like grab bars were not installed, wood blocking was installed in the walls to accommodate their installation later.  The plumbing for the sink also comes out of the wall, not the floor, so that in the future a wall-mounted sink could be installed to make the bath ADA compliant.

 

 

Water heating

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In the Zero Energy Ready Home we chose to use a Navien tankless ultra-condensing water heater, model NPE-180S.  We found it to be the most efficient natural gas water heater we could find at a decent price.  In fact, the unit with the flush valve kit included only cost about $400 more than a standard power-vent tank water heater.  It also has a 15 year warranty on the heat exchanger, whereas a power-vent model only has a 6 or 9 year warranty on the tank.  Also, even the best power vent water heaters are only about 70% efficient, so 30% of the energy created when the gas is burned goes right out the exhaust and is wasted.  The Navien unit has an incredible energy factor of .97, meaning that almost 100% of the gas burned goes directly to heating the water.

The unit draws its own combustion air from outside, not extracting heated air from the home like other models.  And the best part of the tankless unit is that it only comes on when hot water is called for.  Any other time of day it is off and using virtually no power (except the LED read-out), unlike a tank heater that must occasionally turn on to maintain the temperature of the water in the tank.  To find out more about the water heater we used, follow this link:

http://us.navien.com/Product/Page1/Details/NPE-180S?Category=NPE-S%20series

 

House complete!

We’re finally done!  The home looks great, and is already performing better than expected.  We are anxiously awaiting the Home Energy Rating Score (HERS) and other stats, which we will share as soon as they available.  Some preliminary data is showing a HERS below 50, with total annual operating costs under $900.  This is more than 50% more efficient than the 2006 energy code.  There is no cross-reference yet from the HERS to the newest (2015) energy code, but the home is at least 10-15% more energy efficient than that code, which went into effect only a few weeks ago.  The image below shows the HERS scale.

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Other preliminary data that we have so far is showing that heating will represent less than 25% of the home’s energy usage, and water heating only about 15%.  The largest energy usage of the home is the lights and appliances.  We installed all LED lights and Energy Star appliances, so there isn’t much more we can do to reduce that number.  It just shows how little energy the home itself costs to run by being built with energy conservation in mind.

Another benefit of the tight, well insulated home is comfort.  I was in the home doing a final inspection of the work and filling out paperwork last week for about an hour.  In that time the furnace never came on, and it was 25 degrees outside.  The thermostat read 64 degrees, but I was comfortable in short sleeves because there was absolutely no draft.  Since air movement in a home can lead to a significant difference in how a temperature feels to us, that 64 degrees felt just fine.

As part of our final testing of the home by our third-party energy rater, a blower door test was performed to test the air-tightness of the home.  A fan and frame are placed in an entry door and the fan is turned on to blow outwards, which simulates a 20 mph wind on all sides of the home.  Anywhere air can leak into the home is tested with a smoke stick, and in this home we almost couldn’t find any visible leakage whatsoever.   The cubic feet per minute (cfm) of air moving through the fan to maintain a certain vacuum pressure in the home gives you the leakage of the home.  For those of you interested in numbers, the home tested at just over 200 cfm at a negative pressure of 50 Pascals.  This was our best test on any home to date by far.  The image below shows a standard blower door (not from our home).

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For those of you who are more visual, a standard existing home has an air leakage that represents a small window being left open year-round, and a newer home something the size of a doggy-door, or maybe a mail slot.  Our home’s air leakage could be represented by a 1-1/4″ diameter hole.   Since air leakage accounts for about 40% of a home’s energy loss, all of this results in very low energy bills and operating costs for our homeowners, now and even more in the future as energy prices inevitably rise.

We’ll be holding a dedication ceremony this coming Sunday for the family, volunteers, and community, and the family should be moving in sometime toward the end of the month.

Stay tuned for more information as the final results come in from our rater!