Design - Sustainable Building Practices - Cont'd

The first post on this topic delt with site selection and house size.  Here the intent is to identify sustainable practice goals and see how well we meet them.

Criteria for Selecting Sustainable Methods and Materials

From the outset, we tried to understand what we needed to do to employ carbon-phobic

methods and materials, based on my research in print and online that went back several years, well before we had even bought land.  Here are the major criteria for selecting sustainable methods and materials that I came to appreciate.  Most of them are covered in the two books shown here (click on images to enlarge).

• Embodied energy used in manufacture or extraction
• Embodied energy used in transport to building site
• Amount of finite resources in the material, like petroleum or old-age timber
• Amount of recycled content in the material, like in steel roofing
• Amount of toxic waste sequestered in the material, like fly ash in concrete and drywall
• Recycled material instead of new, like salvaged lumber and old limestone foundation stones 
• Minimal waste of materials during construction, like using dimensions that utilize off-the-shelf lumber sizes
• Advanced framing or better
• End-life disposal:  recycled (steel roofing) vs. landfilled (asphalt shingles)
• Amount of volatile organic compounds (VOCs) in the material, like in adhesives, finishes and floor coverings

Sustainable Practices Discussed in Other Posts

Sustainable practices that we have already employed or will be employing and that I have already or will be discussing in many other posts bear mentioning here again:

• Frost free shallow foundation
• Wall trusses that maximize insulation and minimize thermal bridging
• Hinged fiberglass windows and doors with insulated low-e glass
• Rice hull insulation; R-60 to R-72 walls and ceilings
• Blower door testing for air infiltration
• Slab edge insulation (in conjunction with frost free shallow foundation)

  

  Slab floor construction with slab edge exposed

• Fly ash concrete and drywall
• Framing with wall trusses made from recycled dimension lumber
• Steel roofing and wall cladding
• Passive solar conditioning; no energy-gulping conventional heating or air conditioning (references to the AGS system appear in many prior posts starting with first post on Annualized GeoSolar) 
• Airlock between living space and exterior doors
• PEX plumbing system
• Tankless water heater with underground "homeruns" to hot water faucets
• Low-flow faucets; dual-flush toilets
• Energy recovery ventilator
• LED lighting with motion activated switches and task lighting
• Kitchen cabinets, built-ins and casework from locally harvested hardwoods
• Retaining walls from recycled limestone
• Numerous rain gardens to capture surface runoff until it can soak in
• Landscaping with native plants

Striking a Balance

Unfortunately, we have found it impossible always to follow the best practices for sustainability due to circumstances beyond our control.  For instance, my original plan was to use gravel from recycled concrete for the sub-base under the slab-on-grade floor but the recycler did not have a slinger truck for spreading the gravel.  I thought we would use it also for the driveway but found out that it contains rebar fragments that puncture tires.  We may have trouble buying drywall containing fly ash and the floor was poured too late in the season such that the "winter mix" did not contain fly ash. And I am sure there will be instances when we will have to compromise for budget reasons such as giving up on using a damp-proofing material for the earth contact wall made from recycled asphalt shingles that was several times more expensive with less functionality, as it turns out, than the method we ended up with.

Impacting the Sustainability Movement?
I think most would agree that our project will still set a reasonably high bar for sustainability. As explained in an early post, we understand the limited impact of one little project like ours on the big picture but the chances are it will have some effect. At the time of this writing, (April, 2016) page views (hits) to this blog numbered over 6,000 with nearly a third coming from foreign countries.  The last check before publishing this post showed the following distribution among the top ten countries represented:

               -  U.S.                                              4,148         (69%)
               -  Russia                                             385
               -  Canada                                           147
               -  France                                             143
               -  Brazil                                               126
               -  Ukraine                                           114
               -  Poland                                              99
               -  China                                                67
               -  Germany                                           64
               -  United Kingdom                                 54

The other 700 visits originated from places all over the world like Indonesia, Japan, India, Scandinavia, Africa,  Australia, New Zealand, Turkey and the middle east.  Are we impacting the sustainability movement?  One can only hope that a modicum of folks somewhere have gleaned a few useful grains or at least have begun to think about sustainability.

*     *     *     *     *     *
Update, summer of 2019:  the number of page views to the blog has grown exponentially until they number just under 100,000. 

Update, summer of 2024:  page views now are 180,000; not overwhelming but, considering the limited audience, enough to make blogging on sustainability worthwhile.