Yes, the details of how to do a sloped sill are not very firm in my mind yet. Since my exterior is thin brick I intend to simulate a sloped brick sill with the thin brick. That means a sloped support structure to support the thin brick. Since my rough opening is 2" oversize I'll need 13/4" under the window but a slope on the outer portion. I may start out with 1/2"plywood over the rough openings in the stud walls and just accept the thermal hit. Then add strips of 1"plwood under the support points and 1"eps to the portion inside of and under the window and a piece of 1/2" sloped plywood on the strip that's outside the window proper then cover the "composite" with a full width piece of Thermoply (bent at the outer edge of the window). Hopefully I can spray foam the tapered space between the 1/2"plywood. The Thermoply will be taped with 'flashing" tape before the window is set. I plan on using shims between the window and the Thermoply at each attachment point and a screw through the window frame at each attachment point. I might use gaskets between the window and the Thermoply, if not caulk or spray foam.

Liebler,
check out my latest design here , it may give you an idea.

You can also rasp EPS foam into a bevel shape. You can make your own rasp easily if you can source 16-20 grit sandpaper, Just glue it to an old trowel. Makes a big mess when you rasp though. Otherwise you can get nichrome wire and a battery and cut the EPS on a bevel. -Guaranteed to work better than spray foam. Think about how many lineal feet you are going to use. Will be worth it to do it right.

I haven’t been convinced that the EPDM gaskets work any better than the standard inexpensive backer rod. It is resilient, non-sticky and should allow movement of the surfaces it touches. Also,if needed, a similar wider material is used for concrete expansion joints.

KB,
I can;t seem to see your current design, perhaps you would be so kind as to email it to lieblerjatwindstream.net
Thanks for the hint (rasping the EPS).  I have several tools that'll make that a trivial task, one is an air powered 12"long sander typically used in auto body repair to shape 'bondo', the other is called a "sureform" tool.    By using the rasp the foam idea I can make the sill very much like the head and jambs with flatwise 2x4s running between 2x2 s on the inside and outside rough opening  with 1 1/2" foam between except that the 2x2 under the outer bottom will be custom ripped, at the sill slope, to an appropriate dimension (about 3/4"). Then both foam and the 2x4s will be rasped from the line below the final position of the outer edge of the window to the custom ripped 2x2.  Then the Thermo-ply will be scored on it's bottom side at the window's outer face position so that it will bend easily in a straight line directly under the window's outer edge.  Then the Thermo-ply will be attached.   2 pieces of 2x4 as thermal bridge is about 1/2 the area of the 1/2"plywood.  I'm thinking that for my 32"x64" casements I'll use 3 fasteners on each long side and 2 on the short sides.  This is definitely an area I'll not trust to any contractor!

Yes, you can use just about anything to rasp foam. It shapes easily. In a pinch, borrow your wife's cheesegrater. Surfboard makers even use a rotory planer. The power tools can easily become overkill though. Google "EIFS rasp" to see standard tools. My rasp is about 10 by 12 inches, to get an even flat surface. (jpg sent)

KB,
After reading another thread here regarding condensation on windows I've changed my mind and now favor a more inward location of the windows, "allmost innie". My new thought is to position the window where it would be with a simple 2x6 wall even though I'm mounting it in a 2x4 inner wall. I'll still frame the opening in the stud walls with a ring of 1/8" thick Therm-oply. I can make the sloped sill by simply cutting the jack studs that are under the outer wall's member across the opening a bit shorter and on an angle of say 5 degrees. The bottom piece of the Thermo-ply ring can be scored on it's bottom side where it crosses the outer edge of the inner wall The score will result in level Thermp-ply over the inner wall and the sloped sill beginning there. The Thermoply "ring" will be "flashed" with flashing tape to the house-wrap over the exterior fiberboard. The windows will be attached with screws through shims into the rough opening in the inner stud wall (or self shimming screws) caulked and foamed to the Thermo-ply. A MUCH simpler structure with substantially better thermal performance!

According to the data I've seen, an innie is about 90% as effective at preventing thermal loss as a halfie so I imagine an "almost innie" would be far superior to an outie. The only problem with really thick walls is the overhang/surround hang, promoting tunnel vision of sorts and a bit less solar gain. Some designs bevel all 4 sides for a funnel rather than a tunnel.

Here is my table of comparisons of various sliding glass doors. My target goal was Cardinal 180/180 or 272/180 with or without i89 innermost coating, Argon fill. Some manufacturers do not make that exact combination. Some mix AR/KR, some use multiple glass suppliers, some have 270 instead of 272 some have i81 instead of i89... I have included a few non Cardinal for reference purposes. In the table CR is for Condensation Resistance.

I have spent several hours on the NFRC database and yes, I am a data nerd.

Co	Manufacturer Product Code	U-val	SHGC	VT	CR	Product Description
Inline	Cl-arg-HS1-arg-HS1 4, se, Foam	0.17	0.44	0.53	72	Fiberglass w/ foam-filled insulation/Fiberglass w/ foam-filled insulation, Fill 1: ARG/AIR (90/10),Fill 2: ARG/AIR (90/10), LowE, CL, No Grid
Inline	LS2-arg-Cl-arg-HS1 4, se, Foam	0.17	0.28	0.48	72	Fiberglass/Fiberglass, Fill 1: ARG/AIR (90/10),Fill 2: ARG/AIR (90/10), LowE, CL, No Grid
Loewen	LE272-LE180-i89 N	0.16	0.28	0.47	59	Aluminum/Wood Composite/Aluminum/Wood Composite, Fill 1: ARG/AIR (90/10),Fill 2: ARG/AIR (90/10), LowE, CL, No Grid
Loewen	LE180-LE180-i89 N	0.17	0.41	0.52	59	Aluminum/Wood Composite/Aluminum/Wood Composite, Fill 1: ARG/AIR (90/10),Fill 2: ARG/AIR (90/10), LowE, CL, No Grid
Loewen	CL-LE180-LE180 N	0.18	0.45	0.53	69	Aluminum/Wood Composite/Aluminum/Wood Composite, Fill 1: ARG/AIR (90/10),Fill 2: ARG/AIR (90/10), LowE, CL, No Grid
Loewen	LE272-LE180-CL N	0.18	0.28	0.48	69	Aluminum/Wood Composite/Aluminum/Wood Composite, Fill 1: ARG/AIR (90/10),Fill 2: ARG/AIR (90/10), LowE, CL, No Grid
Fiberframe	4 mm LoE² 272/ARG/4 mm LoE 180 /ARG/4 mm i81	0.19	0.26	0.43	57	Fiberglass w/ foam-filled insulation/Fiberglass w/ foam-filled insulation, Fill 1: ARG/AIR (90/10),Fill 2: ARG/AIR (90/10), LowE, CL, No Grid
Fiberframe	4 mm LoE 180 /ARG/4 mm Clear/ARG/4 mm LoE 180	0.21	0.42	0.53	67	Fiberglass w/ foam-filled insulation/Fiberglass w/ foam-filled insulation, Fill 1: ARG/AIR (90/10),Fill 2: ARG/AIR (90/10), LowE, CL, No Grid
Fiberframe	4 mm Clear/AIR/4 mm LoE 180/AIR/4 mm LoE 180	0.24	0.43	0.53	47	Fiberglass/Fiberglass, Fill 1: AIR (100),Fill 2: AIR (100), LowE, CL, No Grid
Fiberframe	4 mm Clear/KRY/4 mm LoE 180/KRY/4 mm LoE 180	0.20	0.45	0.53	52	Fiberglass/Fiberglass, Fill 1: KRY/AIR (90/10),Fill 2: KRY/AIR (90/10), LowE, CL, No Grid
Comfortline	4mm loE180-4mm loE180-4mm i89 Kry	0.19	0.40	0.52	56	Fiberglass/Fiberglass, Fill 1: KRY/AIR (90/10),Fill 2: KRY/AIR (90/10), LowE, CL, No Grid
Comfortline	4mm loE272-4mm loE 180-4mm i89 Kry	0.19	0.27	0.47	56	Fiberglass/Fiberglass, Fill 1: KRY/AIR (90/10),Fill 2: KRY/AIR (90/10), LowE, CL, No Grid
Sunrise	LoE270/LoE270/i89; ARG	0.20	0.20	0.38	57	Vinyl w/ foam-filled insulation/Vinyl w/ foam-filled insulation, Fill 1: ARG/AIR (90/10),Fill 2: ARG/AIR (90/10), LowE, CL, No Grid
Sunrise	LoE180/LoE180/i89; ARG	0.21	0.39	0.49	57	Vinyl w/ foam-filled insulation/Vinyl w/ foam-filled insulation, Fill 1: ARG/AIR (90/10),Fill 2: ARG/AIR (90/10), LowE, CL, No Grid
Sunrise	LoE272/LoE272/Clr	0.23	0.24	0.41	63	Vinyl w/ foam-filled insulation/Vinyl w/ foam-filled insulation, Fill 1: ARG/AIR (90/10),Fill 2: ARG/AIR (90/10), LowE, CL, No Grid
Sunrise	LoE270/LoE 270/Clr	0.23	0.21	0.39	63	Vinyl w/ foam-filled insulation/Vinyl w/ foam-filled insulation, Fill 1: ARG/AIR (90/10),Fill 2: ARG/AIR (90/10), LowE, CL, No Grid
Sunrise	LoE180/LoE180/Clr	0.24	0.41	0.51	65	Vinyl w/ foam-filled insulation/Vinyl w/ foam-filled insulation, Fill 1: ARG/AIR (90/10),Fill 2: ARG/AIR (90/10), LowE, CL, No Grid
Strassburger	272-arg-180-arg-i81, xl	0.21	0.25	0.41	55	Vinyl w/ Reinforcement - Partial/Vinyl w/ Reinforcement - Partial, Fill 1: ARG/AIR (90/10),Fill 2: ARG/AIR (90/10), LowE, CL, No Grid
Strassburger	180-arg-Cl-arg-180, xl	0.23	0.41	0.51	65	Vinyl w/ Reinforcement - Partial/Vinyl w/ Reinforcement - Partial, Fill 1: ARG/AIR (90/10),Fill 2: ARG/AIR (90/10), LowE, CL, No Grid
Strassburger	272-arg-Cl-arg-180, xl	0.23	0.28	0.46	65	Vinyl w/ Reinforcement - Partial/Vinyl w/ Reinforcement - Partial, Fill 1: ARG/AIR (90/10),Fill 2: ARG/AIR (90/10), LowE, CL, No Grid
Strassburger	179-arg-Cl-arg-179, xl	0.23	0.43	0.53	64	Vinyl/Vinyl, Fill 1: ARG/AIR (90/10),Fill 2: ARG/AIR (90/10), LowE, CL, No Grid
Strassburger	272-arg-Cl-arg-179, xl	0.23	0.29	0.48	65	Vinyl/Vinyl, Fill 1: ARG/AIR (90/10),Fill 2: ARG/AIR (90/10), LowE, CL, No Grid
Pella	HP , 3 mm LoE² 270/ARG/3 mm i89	0.23	0.30	0.57	45	Vinyl/Vinyl, Fill 1: ARG/AIR (90/10), LowE, CL, No Grid
JELD-WEN	LE272-CL-LE272 SN	0.19	0.29	0.48	65	Vinyl/Vinyl, Fill 1: AR3/AIR (90/10),Fill 2: AR3/AIR (90/10), LowE, CL, No Grid
JELD-WEN	LE180-CL-LE180 SN	0.20	0.47	0.58	64	Vinyl/Vinyl, Fill 1: AR3/AIR (90/10),Fill 2: AR3/AIR (90/10), LowE, CL, No Grid
JELD-WEN	LE272-CL-LE180 SN	0.20	0.31	0.53	64	Vinyl/Vinyl, Fill 1: AR3/AIR (90/10),Fill 2: AR3/AIR (90/10), LowE, CL, No Grid
JELD-WEN	DP20 NS_LE272-CL-LE180 SN	0.20	0.30	0.5	65	Vinyl/Vinyl, Fill 1: AR3/AIR (90/10),Fill 2: AR3/AIR (90/10), LowE, CL, No Grid
JELD-WEN	DP20 NS_LE180-CL-LE180 SN	0.20	0.45	0.56	65	Vinyl/Vinyl, Fill 1: AR3/AIR (90/10),Fill 2: AR3/AIR (90/10), LowE, CL, No Grid
JELD-WEN	DP20 NS_LE272-CL-LE272 SN	0.20	0.28	0.46	65	Vinyl/Vinyl, Fill 1: AR3/AIR (90/10),Fill 2: AR3/AIR (90/10), LowE, CL, No Grid
JELD-WEN	DP20 NS_LE272-CL-LE180 SN	0.20	0.30	0.5	65	Vinyl/Vinyl, Fill 1: AR3/AIR (90/10),Fill 2: AR3/AIR (90/10), LowE, CL, No Grid
JELD-WEN	DP35/50 NS_LE272-CL-LE180 SN	0.20	0.30	0.5	65	Vinyl/Vinyl, Fill 1: AR3/AIR (90/10),Fill 2: AR3/AIR (90/10), LowE, CL, No Grid
JELD-WEN	DP20 NS_LE180-CL-LE180 SN	0.21	0.45	0.56	65	Vinyl/Vinyl, Fill 1: AR3/AIR (90/10),Fill 2: AR3/AIR (90/10), LowE, CL, No Grid
Simonton	06-05; PD; NF; H5; G00; 060613; 71/38; arg; clr; arg; 71/38; DS/DS/DS; 1.000"	0.21	0.27	0.45	65	Vinyl w/ Reinforcement - Interlock/Vinyl w/ Reinforcement - Interlock, Fill 1: ARG/AIR (90/10),Fill 2: ARG/AIR (90/10), LowE, CL, No Grid
Simonton	11-11; PD; NF; F9; G00; 061313; E180; arg; E180; kry; clr; DS/DS/DS; 1.000"	0.20	0.38	0.49	68	Vinyl w/ Reinforcement - Partial/Vinyl w/ Reinforcement - Partial, Fill 1: ARG/AIR (90/10),Fill 2: KRY/AIR (90/10), LowE, CL, No Grid
Simonton	11-11; PD; NF; F9; G00; 061313; clr; arg; E180; kry; E180; DS/DS/DS; 1.000"	0.20	0.41	0.49	68	Vinyl w/ Reinforcement - Partial/Vinyl w/ Reinforcement - Partial, Fill 1: ARG/AIR (90/10),Fill 2: KRY/AIR (90/10), LowE, CL, No Grid
ProVia	SG400-arg-Cl-arg-SG400, se	0.24	0.40	0.5	63	Vinyl/Vinyl, Fill 1: ARG/AIR (90/10),Fill 2: ARG/AIR (90/10), LowE, CL, No Grid
Fibertec	4 mm LoE² 272/ARG/4 mm LoE 180 /ARG/4 mm i81	0.19	0.26	0.43	57	Fiberglass w/ foam-filled insulation/Fiberglass w/ foam-filled insulation, Fill 1: ARG/AIR (90/10),Fill 2: ARG/AIR (90/10), LowE, CL, No Grid
Soft-Lite,	Ultra S EC (3mm)	0.19	0.25	0.41	70	Vinyl w/ foam-filled insulation/Vinyl w/ foam-filled insulation, Fill 1: ARG/AIR (90/10),Fill 2: ARG/AIR (90/10), LowE, CL, No Grid
Soft-Lite,	1" S500/Cl/S500 K EC (3mm)	0.19	0.42	0.47	70	Vinyl w/ foam-filled insulation/Vinyl w/ foam-filled insulation, Fill 1: KRY/AIR (90/10),Fill 2: KRY/AIR (90/10), LowE, CL, No Grid
OKNA	4mm RLE7138/ARG/4mm Clear/ARG/4mm RLE7138	0.20	0.23	0.38	68	Vinyl/Vinyl, Fill 1: ARG/AIR (90/10),Fill 2: ARG/AIR (90/10), LowE, CL, No Grid

Inline is the clear winner here, especially if Condensation Resistance is a concern. Loewen gets the best U-val with the i89 coating. Let me know if I have inadvertently omitted any major contender.

There isn't any data out yet, but Intus has a new line of vinyl windows. Anyone have any thoughts on their Arcade line? It is spec'd a little worse than the eforte, but it still seems pretty good according to their website. They are supposed to be getting NFRC data in April.

From what I've gathered windows are not all that good of an investment. Does strategic thinking need to occur here? In other words, does it make sense to strategically locate a double pane windows at one compass point and triple pane windows at another? And has anyone looked at where the point of diminishing returns says to NOT spend another dollar?

I believe Martin Holladay on GBA was discussing this very issue recently. I'm paraphrasing but he came to the conclusion that we should just get some of the cheapest triple glazed windows we can find. There are some builders making NZE houses here and they are using Harvey triple glazed @ 250 a window.

Posted By aledoux13 on 26 Mar 2014 01:34 PM
I believe Martin Holladay on GBA was discussing this very issue recently. I'm paraphrasing but he came to the conclusion that we should just get some of the cheapest triple glazed windows we can find. There are some builders making NZE houses here and they are using Harvey triple glazed @ 250 a window.

Yes you guys are right. It is all simply a choice. So, I look up the "Harvey" brand of window in the NFRC database. In their Majestic line when I skip the krypton filled options and get to the Argon 90/10 fill the best triple pane has a U-val of .31. If I continue to the air filled options the U-val is .37. This is probably the $250 window. Compare this to a $500 window with U-val of .16. Double the cost and 1/2 the U-val. I suppose it is all a matter of how big a thermal hole you want in your R30 wall, R3 or R6? Hmmm, how about 2 Harvey triples, an innie and an outie in the same rough opening?

Posted By kb on 26 Mar 2014 11:18 PM
Yes you guys are right. It is all simply a choice. So, I look up the "Harvey" brand of window in the NFRC database. In their Majestic line when I skip the krypton filled options and get to the Argon 90/10 fill the best triple pane has a U-val of .31. If I continue to the air filled options the U-val is .37. This is probably the $250 window. Compare this to a $500 window with U-val of .16. Double the cost and 1/2 the U-val. I suppose it is all a matter of how big a thermal hole you want in your R30 wall, R3 or R6? Hmmm, how about 2 Harvey triples, an innie and an outie in the same rough opening?

Actually they are Harvey Tribute Double Hung U-val .20 R-5. The builder who I was referencing to is Carter Scott and you can read about his design decisions here http://transformations-inc.com/press/ Just for a little background I am hoping to be building my house this summer and would rather have Intus but I have looked at these windows strictly as cost cutting alternative.

Don't forget the air infiltration ratings. Everyone gets hung up on the u-value

Harvey is a decent well made vinyl window; it's not the cheapest out there by any means. There are better windows but there are not many American made wood, clad or fiberglass triple pane windows which are priced anywhere near the Tribute. If there were a triple glazed double hung with the quality of the Marvin Integrity, the specs of the Harvey Tribute and price comparitive to the Integrity, I'd be using them. That's exactly why European windows are so popular.
There is a new window manufacturer starting a plant in Massachusetts who will be building a European style window, and who hopes to compete directly with Integrity on price. Perhaps in a year it'll be a new ball game.

Posted By smartwall on 27 Mar 2014 09:26 AM
Don't forget the air infiltration ratings. Everyone gets hung up on the u-value

Yes, its too bad the NFRC website doesn't have that info. I am finding a wide variation in manufacturer info. Wonder if it is accurate or just fudge factor numbers like it is for garage doors that are not regulated by NFRC.

If a window is up to date it will have been tested by AAMA for air infiltration

Posted By smartwall on 28 Mar 2014 09:11 AM
If a window is up to date it will have been tested by AAMA for air infiltration

According to AAMA test standard, the residential product must not allow more than 0.3 cubic feet of air to pass through the entire manufactured unit per minute, per square foot

Some of the better windows I have been looking at claim get to 1/30th of the given AAMA industry standard. I have not found any table at AAMA or elsewhere giving Air Leakage values for various window products. If one exists, please let me know where to find it!

They don't make it that easy. You have to check and see if the window you're going to use is a member , then check the manufacturers label which will give you the info. If the window you're interested in is a member then they will have the info. The company I deal with has the air infiltration rating for each window in their product book. It doesn't take a too much thought to know that awning and casement windows beat DH windows hands down. So if your goal is low infiltration rates, that is what you should use. For my supplier their best DH rate is .028 and their casement rate is .01. Another window that I've just recently found is made of cellular composite material and the test results leave fiberglass in the dust.

Posted By smartwall on 29 Mar 2014 10:33 AM
They don't make it that easy. You have to check and see if the window you're going to use is a member , then check the manufacturers label which will give you the info. If the window you're interested in is a member then they will have the info. The company I deal with has the air infiltration rating for each window in their product book. It doesn't take a too much thought to know that awning and casement windows beat DH windows hands down. So if your goal is low infiltration rates, that is what you should use. For my supplier their best DH rate is .028 and their casement rate is .01. Another window that I've just recently found is made of cellular composite material and the test results leave fiberglass in the dust.

I was excited to hear that some organization was actually measuring and posting window leakage rates. I was disappointed to see that the AAMA site did not have very many manufacturers listed, and I did not see the results in terms of air infiltration for the few that were listed.

It is also important to keep in mind that a window that actually meets the standard maximum leakage rate of 0.3 cfm per square foot does not result in much of a financial loss for many homes and heating systems. For example, on this forum there was a previous discussion of a house with 836 sq. ft. of windows, which I would consider a lot of window area for a modest size home designed with energy conservation in mind. If that house were heating with a high efficiency natural gas furnace with a natural gas cost of $0.72/CCF, and had annual heating degF days of 7000 (pretty significant amount of cold weather), then the annual savings with switching from windows with a leakage rate of 0.3 cfm/ft^2 to 0.05 cfm/ft^2 would be $8.96 per year. So over 25 years, the savings would be $224. How much extra should you pay per window to save a total of $224 over the approximate lifetime of the windows?

Would you want to give up the superior ventilation characteristics of double-hung windows to save this amount? Perhaps not if natural ventilation is a part of your HVAC strategy. What would it cost to add and operate an air-conditioning system over 25 years compared to a home that can be cooled with natural ventilation using windows with better ventilation characteristics.

So do most standard windows meet the 0.3 cfm/ft^2 spec? It seems like a saw an old paper that indicated that about 2/3's of the windows met either that spec, or the one based on linear sealing dimensions. It would be nice to have that included in the NFRC testing, but it is not.

Posted By Lee Dodge on 29 Mar 2014 05:44 PM

Would you want to give up the superior ventilation characteristics of double-hung windows to save this amount?

Superior ventilation characteristics? A casement or tilt and turn window provides 100% ventilation when opened. I don't see how a double-hung window would qualify as a form of superior ventilation when a casement or tilt & turn in the same size will have better ventilation and offer a better window sealing than a double-hung.

Double-hung windows are typically an old carry over that HOA's who don't know better and force homeowners to get such windows. I have yet to see double hung windows being used in a Passive House design. Why would you? There are better alternatives out there like casements and tilt and turn.

According to Green Building Advisor building science experts, they state:

"Look for windows with a leakage rate no greater than 0.03 cubic feet per minute per square foot. Properly sealed windows also reduce outside noises. Generally, double-hung and horizontal sliding windows have more air leaks than casement windows where the sash closes tightly against a gasket. "