Triple-pane windows? Cathedral ceiling with Roxul? Minisplit? Affordability?
This might not be the forum for this long question, but, I’m driving myself a bit nuts with all the environmental/aesthetic/monetary values I’m trying to blend in designing and building our house. Maybe there are a few builder-psychologists willing to give council so as to arrive at a workable blend… and to quiet the competing voices bouncing around in my helmut.
We are trying to juggle the long term benefits and values (both environmental and economic) of making the house extremely easy to heat in a climate that often feels like Siberia, while we keep in mind a wish for frugality as we realize the work that we find most fulfilling often pays the least.
My main questions concern windows, the roof and a mini-split in this context:
a.) 650 sq.ft. relatively energy efficient house in the woods of western Wisconsin, zone 6.
b.) 5 double glazed-argon filled Kolbe windows, and fixed pane windows I built using Cardinal Low-E argon gas filled patio door glass blems — passive solar design, tightly built 6 years ago.
c.) hydronic in-floor heat, off-peak electric micro-boiler I installed, acid-etched slab on grade, 2 inches foam beneath. No HRV.
d.) R-26 walls, but only R-40 closed cell rigid XPS foam sealed with foam, a hot roof.
e.) AC window unit for the worst days of summer, cumulatively about 3 weeks a year.
f.) 690 sq.ft. addition spread over 2 floors, slab on grade with an upstairs bedroom.
g.) R-36 walls, R-58 cathedral ceiling/roof 3/12 pitch with standing seam metal roofing, 4″ under slab and on foundation.
h.) Hydronic heat in slab (same boiler, which was sized for this originally) I’ve installed, so for a few $hundred in tubing we have comfortable back up heat on the ground floor. There will also be a wood-stove which will get used daily. I’m also considering a mini-split installed in the upstairs bedroom for occasional back-up heat and AC. I will add an HRV.
i.) I’m doing most of the work, as I did in the original small house. (I was a builder for 12 years and am now a furniture maker/designer).
Where I’m stuck:
1.) I’ve been planning on triple paned windows and have gotten bids from Intus and Kolbe. The Intus windows (open in) and are very impressive… expensive, but for what they are, a good value. Kobe’s (open out), are a 5 $thousand less, but not as carefully engineered, though aesthetically more consistent with the existing windows. In the first phase of construction I installed 5 Kolbe openers and built 5 fixed panes (costing $140 each in materials). I could do the same in 2nd phase. I could also well as spec dbl. panes rather than triple.
2.) We will have a woodstove which will be our primary heat source, so I imagine triple pane windows don’t make sense in terms of payback, but I feel some responsibility to the long term energy use of the home from an environmental perspective…. and they’d be more comfortable and condensation would be eliminated in below zero weather (over 50 nights this winter).
3.) we don’t have a lot of money (but we can find a way to buy triple panes) and want to pay off our home equity loan quickly.
I’ve boiled down this scenario to these Questions:
~ Is it worth getting a mini-split for the bedroom, when back up heat upstairs would be very sporadic and we only need AC 3 weeks a year? A better option?
~ Triple pane windows even though (in the short-term) they don’t make sense economically?
Anyone have experience with Kolbe triple panes?
~ I don’t like to use foam where I don’t need to (mostly for environmental reasons and toxicity potential) and am considering an “unvented roof”, using Roxul batts and rigid foam on the warm side, carefully sealed. Am I looking for trouble down the road?
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