The New York TImes reports that many LEED-certified buildings are not living up to the energy-saving potential promised by their design. The USGBC is going to change certification to require 5 years of energy and water bills in order to keep a building's LEED status. I am feeling pretty confident that our house, built using PassiveHaus principles, will perform outstandingly in terms of energy savings. We'll keep the records to prove it so that, if we do get LEED certification, in five years we won't have to give it back. The Farmer's Almanac predicts numbing cold this winter. I say, "bring it on".
GIven the tight envelope of our home, the avoidance of Volatile Organic Compounds, or VOCs, becomes even more important. Chemicals in paint, cabinets, carpets, and anything that is brought into the house can continue to emit from their source over time. Carpet absorbs these compounds and emits them over an even' longer period.
Paint chemistry is very mysterious, given the competition among manufacturers and their reluctance to share the ingredients of their "secret sauce". But given that paint occupies so much of the surface of our interiors, and given that we are exposed to the chemicals in paint both during its application and during months and even years afterwards, it is important to know what's in the paint.
Good luck: aside from the degree of VOCs in the paint, manufacturers aren't required to disclose anything on the paint can label. Claims about VOCs are tested before the maker can tout them, however, so that becomes an important way to gauge the "greenness" of the paint.
"The home that David and Carol Gulyas are building is based on many
of the cutting-edge concepts in green construction and energy
conservation, and while it most closely approximates concepts employed
in the German passive home, there are differences.
'The German model really emphasizes being airtight, and while
that’s a fundamental concept in this house, too, we have a different
attitude about quality of life,' Gulyas said. 'In Bloomington, we like
to open the windows and let the air in. Feel a breeze. So we’ve
incorporated systems to accommodate that as well.'" --Mike Leonard, Bloomington Herald-Times, May 17, 2009.
Systems and features that will make the house so radical include:
Plus some not-so-radical features such as excellent construction quality provided by Chris Sturbaum's Golden Hands Construction crew, and outstanding interior design and construction management provided by David Gulyas (full disclosure, the latter is my husband).
The good weather of the past week allowed the crew to make quick progress in putting up the siding. We are using cement board because it is available locally, lasts for fifty years, and is made from wood pulp, cement, and water. It resists insects and requires little to no maintenance. It is pre-primed a beige color. Stand by for the sage green color we plan to paint the exterior.
For the trim, we're using MiraTech, a silica-free machine-made material that resists water and takes paint beautifully.
This past week the extruded polystyrene (XPS) is being laid down over a bed of gravel and sand, within the insulated foundation walls of our house. This 10.5-inch layer of XPS will be topped by the actual concrete slab, which will "float" upon the XPS, resulting in a thermally decoupled slab!
Structural Insulated Panels (SIPS) will be erected upon the foundation walls. Adding 10.5 inches of insulation under the floor slab is radical, at least when compared to current practice, which is typically a one-inch layer. The resulting "R" value, will be about R-50, pretty much the same for the 12" thick walls and ceiling SIPs.
Anyone who has sat on a carpeted floor in a typical Midwest house in winter can attest to the fact that one inch is not sufficient to prevent heat loss through the floor.
We had to insist that the workers laying the XPS, lap the pieces so that there were no deep cracks that would allow air or moisture to move from layer to layer more easily.
We were glad to find that we could get reclaimed XPS from Plywood King
in Spencer, IN. Though Marko Speigel, our energy modeler and guru of
all things green built, was skeptical when we proposed using reclaimed XPS, the quality of the material we received was excellent. We had very little waste XPS remaining after the installation. The XPS will be disposed of by incineration; when burned, XPS is about the same as burning wood, and therefore emits no dioxin products into the air.
It sure is nice to be married to an Interior Designer. Here is the design of the kitchen, which we hope to begin work on in the spring, after the house is closed up. (We are still in the foundation phase at present.)
Planned green features include:
Finished concrete floor, stained and sealed
Locally, sustainably harvested wood for cabinets
Energy Star appliances, including an induction cooktop (which are all electric and energy usage can be offset by the planned 2.5KW PV system)
LED and/or infrared halogen lighting throughout
Low-flow water fixtures
The rendering above was done using SketchUp. It shows the high degree of daylighting that will be provided by the open design and clerestory windows.
It's exciting to see the foundation being poured on our green-built house in Bloomington, Indiana. Here, Mick's crew from TPC (Trevor Powell Concrete in Gosport, Indiana, pours the foundation footer,using concrete composed of recycled slag and fly ash.
Structural Insulated Panels (SIPS) are made from a thick layer of foam sandwiched between two layers of Oriented Strand Board (OSB), made of plywood or fiber-cement. "The result is an engineered panel that provides structural framing, insulation, and exterior sheathing in a solid, one-piece component." (Toolbase)
--SIPS are extremely easy and quick to install; since they come from the factory pre-constructed to your specifications, your walls can be up in three days
--They are long-lasting and durable
--SIP-built homes are quiet
--They can be adapted to nearly any type of building design
--They provide superior insulation -- no more cold walls in winter!
Porter SIPS, in Holland, Michigan, is within the 500-mile radius required by LEED-H specifications to allow a material to be designated as "local". Porter SIPS' price came in thousands of dollars lower than Insulspan's,
another leading manufacturer. In addition to offering a price
advantage, Porter will send a consultant to help advise during the
installation process. Image Credit: The Murus Company, Inc.
On Tuesday, if the weather cooperates, we are scheduled to break ground on our green home and we are very excited. Handling the contracting will be Golden Hands Construction of Bloomington, Indiana. Chris Sturbaum and his crew have a golden reputation among Bloomingtonians for quality and an understanding of what makes homes beautiful, efficient and enduring. As we begin construction in an effort to get the house shell up and closed before winter, my postings will increase in frequency.