Thursday, April 02, 2015

Environmentalism vs. the environment, again

Apparently, one of the hot new moves among environmentally conscious college graduates with worthless degrees is to build themselves a mini-home on a trailer chassis.   The new homeowners are young, generally childless and often single, and quite frankly, many of the homes they're building are really pretty attractive.

But that said, you knew that I'm not talking about this to give a clear compliment, of course.  Let's take a look at how "environmentally sound" these things are.  They range from 18-20' trailers weighing in at about 6000 lbs. to 24' trailers weighing in at 8000 to 10000 lbs.  Not surprisingly, the tow vehicle is generally a 3/4 ton or 1 ton pickup to pull these 100-160 square foot "dream homes", getting about 10mpg towing and 15mpg or less without towing--and that with the diesel engine.

Let's compare, for what it's worth, with another mobile home with about 150 square feet, the Airstream Flying Cloud 19'.  Like the Tumbleweed, it costs about $60,000, and like the Tumbleweed, it has about 150 square feet with kitchen, bathroom, bedroom, and dinette/living room area. 

Leaving aside aesthetics for a moment, the big difference between it and the Tumbleweed is that (a) the Tumbleweed weighs 1-2 tons more and (b) the Tumbleweed is about 3-5' taller with about 2-3 times the wind resistance.  So while the Airstream uses more "non-renewable materials" in its construction, it strikes me that if you really want to strike a blow for the environment, the Airstream--which can be towed by many minivans and SUVs--is really the better choice.  Even the largest Airstream--31' , 250sf, and 7400 lbs--can be towed by today's half-ton pickups. 

Put gently, the extra ton of metal used by an Airstream, and its carbon footprint, is quickly matched by the extra ton of metal needed to tow a Tumbleweed, and the fuel used only makes the situation worse.

So if you're smitten by the tiny home movement, don't let me stop you.  I think they're cool in many ways.  However, if you want to tell me how environmentally sound you're trying to be, you might want to consider emulating what Airstream has done.  Use lightweight construction methods, build past the ladder frame to get more room over the wheels, and for goodness' sake streamline that home a bit if you're going to be towing it much.

One final note; having watched the video of Airstream construction, it's cool, but if you really, really wanted to make that thing about 1000 lbs lighter, you'd end up using monocoque construction instead of body on frame.  Would it last?  Well, it's about the same construction as a modern jet plane, which can last 50 years despite the stresses of 500mph flight. 

No comments: