The Two Roads to Energy Efficiency
July 11, 2011
Guest Author: Michael Mancini – Purchasing National Homebuilding
A new Meritage advanced solar home uses about one-fifth of the energy than today’s previously owned homes use.
How do we do it?
A Meritage home works as a system. The mechanical system, insulation, windows, lighting, plumbing fixtures, solar components, and other features all work together as one.
But what if you were to try to convert a home on the market today, a home that’s ten or fifteen years old, into something whose energy profile is comparable to a new Meritage home?
First, you’d have to address the insulation in the walls. You’d have to either tear out the stucco and the brick or siding, or tear out the interior drywall, and that tear-out will cost you around $1,000 to $2,000. Not to mention the home is virtually unlivable while the tear-out process is underway.
Now that the walls are open, you’d have to replace the windows. To replace the windows in a previously owned home with the windows Meritage uses could cost $15,000 to $20,000.
Next, you’d have to re-insulate the walls. You’d have to remove all of the old the insulation and re-insulate with open-cell, polyurethane spray-foam insulation, an improvement that will set you back about $5,000 to $10,000.
Next is the attic assembly. Meritage applies open-cell spray foam to the underside of the roof deck, meaning the entire attic space is within the home’s conditioned space. The mechanical system is within the attic’s thermal envelope, making the home essentially one big encapsulated shell. Compare this to a previously owned home, which has insulation at the ceiling line. In the summertime, attic temperatures can exceed 150 degrees Fahrenheit, making the attic a less-than-ideal spot for a cool-air delivery system’s duct work. To change that in a previously owned home, you would have to remove all the insulation from the ceiling and apply open-cell spray foam to the underside of the roof deck. Total cost: $6,000 to $10,000.
Now you’ve created a fully encapsulated thermal envelope, and you’ve got everything inside your conditioned space. It’s just like a Meritage home, right?
Wrong.
Unfortunately, the previously owned home’s existing mechanical system is now completely inefficient. That system was designed to combat all of those heat loads from the walls and the windows and the hot attic, and now those heat loads aren’t there anymore. That means the mechanical system has to be completely redone. A 14 SEER properly designed mechanical system, with a fresh air management system, retrofitted into a typical home will cost anywhere from $20,000 to $30,000.
After that, you’d have to upgrade light fixtures to high-efficiency compact fluorescent fixtures. You’d also have to update all of your plumbing fixtures to EPA Watersense fixtures. You’d have to update your irrigation system to a weather-sensing zoned irrigation system. All of those components can cost anywhere from $2,000 to $5,000.
After that, you’d have to replace those old appliances with Energy Star appliances. A mere $2,000 to $5,000 will get that done.
Oh yeah…don’t forget about the $25,000 Echo solar/thermal system!
The total cost for turning a previously owned home into a home as energy efficient as a Meritage home? $80,000 to $120,000.
And now you can move back into your home after living with friends for three months.
With a new Meritage home priced at roughly the same as today’s previously owned homes, there’s only one question to ask.
Why would you choose anything else?