Sustainable or "Green" Building Protocols

The Sustainable Buildings Industries Council (SBIC) defines sustainable or "green" building as a whole building design approach to materials, systems and assemblies aimed at effecting "cost, quality-of-life, maintenance, future flexibility, energy and resource-efficiency, overall environmental impact, productivity, creativity, and ways the occupants will be enriched and enlivened by their surroundings".

That is a tall order but we believe our houses meet it. Passive solar construction in itself achieves most of the goals mentioned above, and AAC walls do much of the rest. The two systems together employ materials that are mostly renewable and recyclable, non-toxic, and they can produce zero-energy use houses.

Sustainable or green building guidelines primarily address the problems of energy use: housing accounts for 20% of the total energy devoured in the US, just in construction and maintenance, and not including the energy needed to heat and cool them. The SBIC states that applying sustainable design principles to the future housing stock could reduce that figure by 30-50%.

Our houses go beyond this target reduction in energy use.

Many SBIC recommendations for achieving this reduction are addressed to the problems of building with wood, and so are irrelevant to AAC houses. Although we are quoted in the SBIC book Green Building Guidelines, we differ with a number of its recommendations for the use of wood and related poisonous synthetics, both of which we try to seriously under-employ. Framing, flashing and wall cladding recommendations are irrelevant to AAC, which has none of the problems targeted by the SBIC. Our houses don't require synthetic wall claddings, wall vapor barriers, or synthetic wall insulation, all of which are toxic petroleum derivatives and hazardous to manufacture.

We dispute the Sustainable Building Council's endorsements of insulating products with HCFC's (hydrochlorolfluorocarbons), HFC's (hydrofluorcarbons), or "better yet" they say, "those that use CO2, pentane and isobutene". They also recommend the use of OSB board, which is now an industry standard; OSB is manufactured using phenol formaldehyde and methyl-diicocyanate; OSB outgases formaldehyde for years and at three times the EPA's current standard for public health; it is a suspected human carcinogen and is implicated in the growing US asthma epidemic.

We recommend avoiding all of this stuff! Who needs it?

Crawl spaces are specifically omitted in our designs, so omitting all of the questionable materials and techniques used to waterproof and insulate them. We do find it necessary to use rigid polystyrene and 6ml sheet plastic under our slabs, but otherwise avoid most synthetics. We recommend fire retarding borate-treated cellulose insulation over the use of fiberglass in ceilings, and as sound insulation between walls. Air infiltration in AAC walls is 67% less than that of conventional insulated wood framed walls, obviating SBIC remedies to this problem.

Roof trusses are a green product because they use so little wood compared to conventional framing; and what wood is used is short in length and smaller in dimension. Most of our roofs can be constructed without the use of OSB, another polluting, off-gassing product (and it is also obviated in using AAC wall systems).

We now specify the use of much deeper insulation in preference to using radiant barrier products.  (In North Carolina, we now use R-60 borate-treated blown-in cellulose insulation, rather than our former combination of a radiant barrier and R-36 insulation.)

Steel roofs are a green product because they last so extremely long without maintenance or replacement. We recommend Pittsburgh Paints No-VOC (volatile organic compounds) products.

We also recommend installation of solar hot water heating systems; if it is not possible to install a system at the time a house is built, we specify that the house be pre-plumbed for later retrofit.

Our houses are photo-voltaic friendly, but because of their low use of conventional electricity, the payback period for a PV system can be very long. However, any house built in a remote site can incur such extreme costs for bringing in conventional electricity that PV systems may make good economic sense.

We subscribe to the guidelines set forth by the Sustainable Building Industries Council with regard to maximum home size; these figures do not include porches, basements, garages or outbuildings.

  • One bedroom: 1700 square feet
  • Two bedrooms: 2000 square feet
  • Three bedrooms: 2300 square feet
  • Four bedrooms: 2600 square feet
  • Five bedrooms: 2900 square feet
  • Six bedrooms: 3200 square feet

Many recommendations for sustainable or "green" houses are the province of the homeowner, not the designer or builder. We include Sustainable Building Industries Council instructions for "green living" with our construction notes. What is the point of making a new "green" house and filling it with energy-intensive, poisonous, and non-renewable accoutrements?