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SomeConstructionGuy t1_j6mzd42 wrote

Reply to comment by Corey307 in Really want to build a house like this. Passive home stays at 70 degrees in Maine w/o furnace. by Twigglesnix

Yeah not sure on the downvotes.

Passivehaus is massively expensive in our climate and has minimal benefit over net zero.

In climates where they don’t get the negative temps passivehaus becomes much more economical.

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Corey307 t1_j6npmz5 wrote

See they are running a heat pump and it cost them nothing but that’s because they’ve invested in solar so between the at least $30,000-40,000 for extra insulation and whatever they paid for solar panels they are spending significantly more over the next 30 years that if they were just heating a house with good windows and reasonable insulation.

I’m not being anti-environmentalism, no lol if you can afford it go right ahead. These are just the thoughts of a blue collar guy that does what they can to help the environment but couldn’t justify spending that much to never get the money back when I could put the equivalent money in high yield mutual funds. Let’s say the extra insulation cost $30,000, that works out to about $83 per mortgage payment over 30 years. If instead that $83 was put directly into a high-yield mutual fund monthly doing an average of 10% over 30 years you have $172,000. These two look like money having been a poor kid that grew up around rich kids, that’s great for them not good for blue-collar people.

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SomeConstructionGuy t1_j6nt3s4 wrote

Few flaws in that argument.

You’re assuming energy prices will remain the same and that the insulation costs more.

We’re getting r32 ish walls for less money then foamed 2x6 walls. The attic is easy, just blown in more. Windows can be just good double pane. Nothing crazy needed.

And you skip the whole heating system and have 2x 15k heat pumps. That’s a savings of 10k or more. Heating with a current heat pump is ballpark same as the cheapest natural gas.

So for the same money you can skip the boiler/furnace, Insulate well, have heat and AC and still pay the same or less for heat. You don’t need to offset with solar that we can agree on for sure.

The air sealing has the added benefit of making your house last longer too.

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Corey307 t1_j6ntlx7 wrote

Of course I’m assuming it cost more since the article said they spent about 10% more on this house than they would a traditional build and building a house these days costs at least $300,000. I get the environmental aspect I’m saying that the financial aspect isn’t great. And r32 is not cheap, I’m not telling you what to do with your money I’m saying that fully insulating the house with it is a major expense. I’m also not quite sold on the airtight house idea since our house is supposed to breathe at least a little bit, if you don’t go outside for a couple days the air is going to start getting pretty stale.

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SomeConstructionGuy t1_j6nud1m wrote

It’s not my money, I’m the builder.

I think you missed the part where I said r32 is cheaper than foamed 2x6. R32 is cheap now relative to just foaming the walls. And just straight batts don’t meet code so you’re stuck with some combo of foam and batts at minimum.

There is no financial reason to not do this now. There’s reasons builders don’t want to, but it’s not money.

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Corey307 t1_j6nwq6y wrote

Thank you, I should’ve known by your name that you knew more than I do haha. Hey I’m not asking for legal advice or anything but if someone wanted to insulate a basement is that something you can do as a homeowner or are Vermont state regulations too strict? Because I was thinking about just laying some R19 between the beams as a balance between cost and energy savings. But if I had to also use foam and then drywall it I’ll probably let the next owner do so. That’s something I missed when I bought the house since I’m originally from a warm climate, I’m disappointed my home inspector didn’t say anything but I heard they passed away so it’s not like I can do anything about it.

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SomeConstructionGuy t1_j6nzw0a wrote

Not strict, go for it!

You want to insulate the floor system between 1st floor and bassment? Batts will work, I’d go with mineral wool since it’ll hold its shape better and mice hate it vs fiberglass.

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Corey307 t1_j6o32g1 wrote

thank you for your help, I’m not trying to fully insulate the basement just trying to strike a balance between reducing heating costs, having a warmer floor during the coldest days and not spending a lot of money. I’m also thinking it would help avoid a sticking point when I sell since I can get this done for about $600 and insulation and maybe $30 for a painters suit, goggles and mask.

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SomeConstructionGuy t1_j6ouufj wrote

Depending where your mechanical equipment, what it is and how it’s insulated you may or may not gain much insulting the floor system. Depending what type of foundation you have (concrete, block, stone) it’s pretty darn easy to install 2” foam on exterior walls. Foam board on the foundation walls will certainly help all aspects.

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