Renewable-energy appliances such as photovoltaic panels, solar hot water heaters, and geothermal pumps are often viewed as fundamentals of green building when in fact they really are just "the icing on the cake," architect and building scientist Peter Pfeiffer told a packed room of home builders on Feb. 13 at the International Builders' Show in Orlando, Fla.
Urging attendees not to repeat the "toy" fixation that dominated the early green movement of the 1970s, Pfeiffer outlined a whole-house approach to sustainable building that advocates energy conservation as a necessary first step before energy production can even be considered.
"In the end, it's all about common sense," said the principal and co-founder of Austin, Texas-based Barley & Pfeiffer Architects (www.barleypfeiffer.com). For example, if electricity generated by photovoltaic panels is immediately gobbled up by an HVAC system that must work extra hard to compensate for a leaky shell, the house is only working against itself.
True sustainability begins with smart design, Pfeiffer contended. "Energy conservation strategies are the low-hanging fruit. They are the easiest to implement at the program/design phase," he said. Efficiencies can be achieved, for instance, by properly orienting and massing a house to exploit or prevent heat gain; incorporating rainwater harvesting systems for irrigation; using deep overhangs and awnings to guard against water intrusion and mold; aggregating sleeping quarters into a single temperature zone that can be dialed up or down; depending on the time of day; and going the extra mile to ensure a tight building envelope.
"Ninety percent of green happens in the first 10 percent of the project," Pfeiffer said. Regional conditions should be a factor in the design. For example, vaulted ceilings are inadvisable in climates that rely heavily on mechanical air systems because they create extra volume space that must be conditioned, cooled, dehumidified, or heated. In hot zones, soffits painted a light, reflective color will produce the same ambient lighting effect as skylights, minus the heat gain.
On the topic of indoor air quality, Pfeiffer recommended making detached garages a part of the site plan whenever possible. "People sit around and worry about whether or not their house has low VOC paints when the much bigger problem is that they are sleeping with their Suburban," he said. Fumes from gasoline, pesticides, and other chemicals can easily seep into the home when the garage is attached to the main living structure.
Investing a little extra money on a high-performance HVAC system is perhaps the best green investment a builder can make, Pfeiffer contended. "Duct leakage in a forced air system will negatively pressurize a house, in which case it will suck in more air from the outside, making the A/C work harder than it needs to. You can put $2,000 to $3,000 into a good metal ducting system that is blow tested, and it will yield a greater benefit than spending $20,000 on a geothermal heat pump. Why not spend less money and do more good?"
Invoking a white paper known as the "R Value Myth," he further asserted that high-performance products should not be expected to compensate for flaws in the building system. Superior insulation will not protect a house from the elements if installed without an effective vapor barrier, and "low-E windows are not a substitute for proper shading and solar control," he said. "A building without weather protection is not green."