In a previous post I posed the question, “How green is green enough?” I was researching green construction practices at the time and the entire green spectrum was becoming apparent.. On one end is today’s standard building code, which ensures all new construction adheres to minimum energy efficiency standards. On the other end are net positive houses which actually generate more energy than they use. Then there is everything in between.
There are 4 major gauges for how environmentally friendly a house is: the Energy Star rating, the HERS Index, the LEED point system, and the Passivhaus standard. There are pros and cons to each, and interestingly these are not comprehensive evaluations. The Energy Star rating and HERS Index focus solely on a house’s energy consumption (see my post Different Shades of Green). The LEED point system is perhaps the most comprehensive because it evaluates indoor environmental quality, use of local and recycled resources, sustainability of materials, awareness education, minimization of waste, plus energy consumption. However it is expensive to get this certification (over a thousand dollars), there is a rigid “point” value system, and it requires extensive documentation on the part of the builder and homeowner. Lastly, the Passivhaus standard out of Germany guides airtightness, BTU consumption (heating and cooling consumption), and energy consumption. The Passivhaus standard is so high that it’s really expensive to build in a cold climate. For example, in order to achieve the Passivhaus standard, one would need to build 16″ thick double studded walls in Pittsburgh (crazy!).
While I’m all for getting a “grade” on my house (total geek at heart), I don’t want it badly enough to go through the exhaustive and expensive LEED checklist, and am certainly not going use the Passivhaus standard as the goal which is impractical for me. I suspect many people out there feel the same way I do, and it doesn’t mean we’re less committed to building green. I just want an environmentally friendly and energy-efficient house that’s a pretty darn good house.
Lo and behold the Green Building Advisor gurus out of Maine came up with the concept of the Pretty Good House (PGH). It’s a “commonsense approach” to home construction that is feasible. Here are the guidelines:
– uses local labor and locally produced/available materials
– minimal and reasonable annual energy cost of $500-700 per year, which is tested and measured after construction
– prescribed insulation levels of 10-20-40-60. That is, R-10 under the foundation slab, R-20 on foundation walls, R-40 in exterior walls, and R-60 in the roof. These numbers may be adjusted based on climate.
-reasonably sized home: 1000 sqft for an individual, 1500 sqft for two, 1750 sqft for 3 and 1875 sqft for 4 and greater.
-energy modeling is necessary to ensure all mechanical systems are sized correctly
-air leakage rate of no greater than 2 ACH50 (I don’t know what that means, either – I will have to look it up 😉
-mechanical ventilation is required since the house is so air tight
-good design, preferably universal design. A house that looks good, feels good, fits its site, and is accessible to the elderly and disabled
– Comfort (no drafts) is a must
– the house comes with an owner’s manual
I’d like to add a few more things to that PGH list:
– non-toxic materials, e.g. low VOC paint
– some element of recycled or salvaged materials.
– at least one renewable resource. Solar energy is one, but I would even consider bamboo flooring a renewable source because it grows so fast!
– efficient space planning. For example, taking advantage of closet organizers to maximize all storage space.
Months from now when my little house is complete, I hope to come back to this checklist and grade my house. Hopefully I’ll get an A :). I am less than a month away from getting my building permit and am super-stoked. Let’s build a PGH in PGH! (Sorry, couldn’t help myself)