We are re-using the vast majority of the materials of the existing residence (rather than tearing it down). . . . We have, as discussed in the previous email, replaced the outdated and inefficient windows and doors with high performance (and sustainably sourced) windows and doors. Furthermore we will be insulating the entire building (original and addition) to beyond code, and providing energy efficient heat and hot water . . . as opposed to allowing an inefficient building to continue to operate for decades more. . . . My assessment is that the gallons of diesel fuel which were consumed in the rock chipping process will negate only a small fraction of the overall energy savings which this house will provide as a result of being properly remodeled with efficiency in mind.
But how do you quantify these things? No doubt the revamped house will be more airtight than the original. But it will also be much bigger. Will extra insulation and high-tech plumbing offset the energy needed to heat all the additional floor space?
There is also much more glass. In an earlier email we read that there will be “passive solar gain” from the front, north-facing side of the house. What that means is many more square feet of windows in what had been a solid adobe wall. Will the northerly windows, overhung by a portal, really bring in a significant amount of heat during the coldest months of the year when the sun has migrated to the southernmost part of the sky? And how is any energy gain in the winter weighed against the extra heat the new windows will admit during the summer when the sun returns to the north?
Mr. Giorgetti concedes that the answers are unknown:
Builders (even green builders) are constantly working against other constraints (construction budgets, building codes and ordinances, client preferences, and other factors) which will influence the decision making process and can, at times, cause diversion from the ideal. We work within an imperfect set of conditions to deliver the best results we can, with sustainability always in mind.
Fair enough. For all the suffering it has caused, the new house will probably be an attractive and well-constructed addition to the neighborhood. But should it be welcomed as a contribution to the environment?
It is the old adobe houses that were sustainable — the ones that are being gutted, hyperfenestrated, and expanded all over town. What is happening across the street from me is a single example of a larger trend. In earlier times people made their walls with the same dirt they shoveled from the ground as they dug a new foundation. Lumber was locally grown, cut, and milled. People satisfied themselves with 1,200 or 1,500 square feet of living space. They conserved heat by minimizing the number and size of their windows. If it was too dark they turned on a light. If they wanted a view they walked outside.
We live in more luxurious times. If you can afford to buy a traditional middle-class home in a historic neighborhood and turn it into a show place, that is your prerogative. You can haul off the funky appliances and haul in stainless-steel upgrades with Energy Star labels, shipped perhaps from a factory in China. You can replace linoleum or talavera with marble, granite, quartz, or the latest new synthetic from Dupont. You can take pride in your sense of aesthetics and good taste. But I don’t think you deserve extra points for being green.