U value vs R value and electrical….food for thought
Something neat I discovered tonight.
Long story short my family member purchased a home that was originally the sales office for a luxury community. It’s modular construction and about 20 years old. It was a 24x56 unit originally, but now has an addition adding some square footage.
A few years ago the community finished up, subdivided the land and converted this place to a house. It was originally installed on a permanent foundation (brought in and put on piers, footers and all trailering hardware removed possible).
Two really neat things I discovered.
First: this place does NOT look modular. Extensive patios installed, full block crawlspace, albeit a handful of things are “modular” in a sense (back door swings out) and the room layout is a tad odd (we’re fixing that).
With a unit as wide as this, it comes in two sections, so that means two full sized electric panels. That has opened us up for extensive space and availability for things such as hot tubs, solar, EV chargers, you name it. 400 amp service in a less than 2k square footage home is fantastic. Doubly fantastic is that it’s two totally independent panels. If you need to shut down for a major repair, half the house still has power.
Another thing and my big point: insulation. This place is insulated CRAZY well. Not only are utility bills low, but especially with the commercial units, these are typically built with Bard wall mount ac/heat units which aren’t super efficient. In that sense, if the building has low heat loss, efficiency isn’t nearly as big of a deal on the HVAC unit (cost/parts savings etc).
U value vs R value. Stick built homes typically are built on R value, where 38 is generally the standard for an attic floor/ceiling and the higher the number, the better. U value on the other hand is inverse, the lower the value the better. Typical U value is a well insulated home is 0.25-0.35.
Modular buildings? U value must be posted on the info sticker. I found the old info sticker. The U value of the floors is a whopping 0.06. Not only is that insane, that’s exceptionally insane. Most homes on basic crawl spaces are quickly and not well insulated. The crawlspace here is easily 20 degrees colder than outdoors and 10-15 than indoors (I assume it’ll be more in summer). The floors are never cold in the living space.
This place underwent a full conversion. High end cedar exterior, residential appliances and drumroll……retrofitted HVAC. It originally had two Bard units. They’re gone. Now it’s a centrally ducted 14SEER (I know, blah) unit. Their originals were 10SEER. Not only does it hardly run, but the ac has barely been needed. The walls have a U value of 0.09. This place is so exceptionally insulated that a standard efficiency unit is still VERY good because it barely needs to run. An hour or two and the whole place is down several degrees. It’s 90 out today. The air ran for a whopping 2 hours.
FINALLY I feel the best perk is that many of these are customizable and approved by most states. This one is fully drywalled with beautiful trim and woodwork.
I also forgot to mention that these units are so well built, that they’re rated for a higher live PSF than most modern homes. Most are around 40psf for residences, this is 50. You cannot tell at all that it’s originally modular because of how solid the floors are. It’s mind boggling.
Expensive? Yes. Easy to build? Yes? Exceptional build quality? Holy schmoly. I’m shocked. Why aren’t more people talking about this?