Natural pool dig begins

After a few weeks of unexpected delays, work on extra retaining walls needed to support the pool was completed last week.

Construction on the natural pool has now begun, with Aquascapes and Biotop at the helm. The pool will use a natural water garden to filter the water. The main design and engineered drawings are complete, and we look forward to seeing those concepts materialize. 

As workers on the ground create substance from vision, we turn our thoughts to plantings for the water garden, landscaping, and interesting ideas for fencing that will be effective and retain the natural feel of this land. Botanical genius, Anthony Archer Wills is working with us to ensure that the environment emerges with integrity, and that the landscaping will harmonize with the site. 

Construction Materials and Air Quality, a Wrap Up

Construction on the Passive House will be complete within the next few weeks. We will then do the final blower door test, followed by the interior fit out, and the house will be complete! It’s been quite a journey from concept to design to construction. We’re all excited to see the final product.

During the process of building this house a review was done for each type of construction material used inside the building envelope, to ensure a clean and nontoxic environment. Working closely with Bill Stratton and our architects at Barlis Wedlick, we compiled a spreadsheet documenting the research on each item.

Previous posts detail concerns with new construction and indoor air quality (Is Green Always Clean?), and list out third party certifiers and IAQ standards (More on IAQ and Making a List). In addition to materials used, this Passive House construction prioritizes a tight building envelope and continually circulating air, which prevents mold growth and keeps the air refreshed and pure. The durability of all materials was considered in addition to their air quality appeal, so that the goals of efficiency and sustainability for the house are also maintained.

Here are just a few of the specific items we have chosen for this Passive House:

  • Drywall: Lafarge drywall and joint compound (Greenguard Gold certified)
  • Wall paint: Ben Moore Aura (Low VOC). Though there are no-VOC paints available, experienced people have shared that they have more confidence in the performance of this product, and that less coats are required than the no-VOC paints available.
  • Construction adhesives: OSI Green Series (Greenguard certified)
  • Wood finish: Bona (Greenguard certified)
  • Grout: Laticrete (Greenguard Gold certified)
  • Plywood for casework, cabinetry: Commonwealth Plywood (suitable for LEED IEQ point, and FSC certified for sustainability)

Materials that are Greenguard certified or that meet the LEED recommendations for Indoor Environmental Quality were generally considered okay in construction of the house.

The UL Sustainable Product Guide is a helpful source for finding products low in Volatile Organic Compounds, or that meet other preferred specifications. Another resource is the Material Safety Data Sheet (MSDS), which usually tells the VOC content (Section 9) and other helpful information about each product, and can generally be downloaded from the manufacturer’s website. Sometimes VOC content is not found on the MSDS, but is contained in other informational sheets. Proper knowledge and application of materials by the construction crew and ventilation is important as well, to protect their safety and to ensure proper curing. Details about maintaining indoor air quality with new construction can be found in the ASHRAE manual, Indoor Air Quality Guide.

A few weeks out from the interior installations at the house.

House Interior Palette Final Decisions

At the house, the floors have been installed and the ceiling begins to go in today. We visit an array of choices to determine final colors for walls, ceiling, floor finish, grout, and more. Subtle distinctions emerge and each selection complements and shifts the spectrum. Each primer, paint, finish, and varnish, respects the integrity of the indoor air quality.

Walls in the house will be a warmer white, and volume masses are to be painted a darker grey. Elaine and Alan show these final selections.

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Complementing that, the ceiling color will be a lighter, almost silvery grey paired with the natural iWood finish on the main posts, referencing the iWood posts at the barn.

The kitchen will carry through shades of black, white, and grey, but will add an irreverent hint of color, a citrus grout for the backsplash tile. Shelving will be framed by bent black metal, open or with frosted glass doors, and mounted on tracks that will reference the barn and a ladder track that will extend over the stairs. Layers of metal will repeat for an industrial aesthetic.

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The house will offer an invisibility to different features - flush doors and handles, simple hardware that minimally extends, and volumes that contain appliances and other equipment to maintain clean lines throughout. Each room will speak to the next, and the overall feel will be open and airy.

Both bathrooms feature interesting moments.

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In contrast to the hues of black and white dominating the house design, each room downstairs will feature a pop of color, either on the ceiling or as an accent wall.

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A more complete picture of the house is emerging. As walls are added, somehow the definition gives the sense the space is larger than when it was open. It won’t be long before all of these pieces merge into the magical place the house will surely be.

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Springtime in the barn

House Construction on Schedule

There’s a buzz of activity at the house. Electrical and plumbing have been roughed in, roof insulation is in, and exterior siding installation is beginning.

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This week the Roxul wool insulation gets installed for the walls, followed by drywall and taping. Roxul is an environmentally-friendly and nontoxic insulation. For drywall, we’re using a LaFarge product that is Greenguard certified.

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The team discusses millwork, which will be customized throughout the house. Any plywood used in the carpentry will be Commonwealth Plywood, which meets LEED IAQ standards and is FSC certified.

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Here, Eric installs one of the HRV air recovery system.

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Flooring installation will begin next week, which will then be finished using a Greenguard certified Bona sealant. We’re researching each product used in the house interior to ensure the highest possible indoor air quality, while also maintaining durability. Subfloor, grout, sealants, all of the above will match the environmental integrity of the house.

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Though there’s snow on the ground, inside the passive house is nice and warm. Extra insulation has been added to the roof, and the overhangs are in which will maximize solar heat gain in the winter and keep the place cooler in the summer.

Andrew and Brad from Dell’s Plumbing are busy installing pipes and roughing in the plumbing. Electricity rough in will begin next week.

2/21/14 Preliminary Blower Door Test Exceeds Expectations

Friday, we conducted a preliminary blower door test at the house to learn where we are standing with tightness of the building envelope.

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Using a powerful fan and a pressure sensitive instrument called a manometer, we are able to determine at what rate air from the outside is exchanged with inside air through leaks in the house. The fan can be used to pressurize or depressurize the house and then measurements are taken. For this test, we attempted both ways to cross-check the measurements.

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In order to meet Passive House certification standards, buildings must score a .6 ACH (Air Changes per Hour) on the test, meaning that 60% of the total volume of air in the house is exchanged per hour.at 50 Pascal. 50 Pascal is the industry standard for this kind of measurement. Most homes in the area score around 7 ACH (code), whereas more efficient Energy Star homes will range from 2.5 to 4 ACH. Our goal for this preliminary test was to score a .25, which would indicate excellent tightness of the envelope and be well within the measurements for Passive House.

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Using a burning stick of incense, Kunal Alaigh from the Levy Partnership, checks by windows and other possible thermal bridges for leaks in the envelope (while making the house smell delightful). He finds a few areas that could be better insulated, good information as the building continues, in anticipation of the final test.

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Our preliminary blower door test calculates out as .178 ACH, exceeding our expectations for the day’s goals! .

Assessing progress at the house and discussing next steps