Sorry if this is the wrong place on the site to post this, not used to this format of forum interface.
Currently am doing a 1:100 drawing of a building for my final first year project. My exterior walls are 600mm (in line with a low energy insulation standard), and I have a large window size glass pane on one of these exterior walls. This window is flush with the outer surface of the wall.
Does anyone know whether there is a different convention for placement of a window line in the drawing and whether it would be positioned differently, as opposed to just being in 'this' format ===----===?
This is a hand drawing if that helps.
Thank you for any answers provided!
Wood Guy
Apr 8, 16 8:15 pm
JTAX, I'm not sure what you mean by "window line or what your dashed lines represent. In any section drawing, if you cut through the material, you show it with solid lines, including glass. If the scale is small, show one line for each pane. If the scale is large, show two lines for each pane, preferably with a hatch pattern at the cut through the glass.
If the window (or other object) is in front of or behind the section cut, if it's an important element you can show it with a dashed line. Use different line types or scales for objects in front of or behind the section cut.
Window manufacturers usually show screens as dashed lines.
cadomestique
Apr 12, 16 4:07 pm
Are you sure you will be proposing 600mm thick walls (23.4 inches)??
I wouldn't call it "low energy std" by any stretch, since you can pack R-21 ins. value in a 6" thick cav. wall, (exceeding required thermal resistance by most codes)
And no, graphically you may show your window as it sits in reality: closer to the outer wall face (not in the middle of wall). Also don't show window operation on plan. Elevations are better suited for that purpose.
Non Sequitur
Apr 12, 16 4:12 pm
^ my codes have been revised as to required exterior insulation beyond the outer face of studs or sheeting so although a 600mm thick wall is big, it's not ridiculous. Kudos to the OP for using Metric units and not the archaic american ones.
Op, I think a section detail would solve all your plan drafting convention problems.
Wood Guy
Apr 12, 16 4:26 pm
The Passive Houses I design often have 18" (460cm) thick walls, and we usually place the windows in the center of the wall assembly, as they perform best at that location, though they are usually installed closer to the exterior plane in conventional buildings.
Code minimum is the worst building you can legally build. High performance buildings can save a significant amount of energy, and can be cost effective over the typical length of ownership. They have other benefits as well.
bowling_ball
Apr 12, 16 9:09 pm
Where to locate the window in the wall plane is an ongoing discussion. Where I work and live, our energy code calls for effective (not nominal) R27 walls. 20" thick walls are common.
Energy modelling has been telling us that the further to the outside of the wall you can go with your window, the better off you are. It used to be all about tying in various membranes, but now even metal pans and flashings are showing up as significant thermal breaks now that our envelopes are so ridiculously tight.
Wood Guy
Apr 13, 16 8:48 am
Bowling_ball, I'm curious about your window placement. THERM modeling has been consistently showing us better isotherms with the window closer to the center of the assembly. You must be in a sunny and cold enough location that the additional solar gains of "outies" are worth it?
curtkram
Apr 13, 16 9:16 am
since your window is part of the moisture/air/vapor system, wouldn't putting towards the outside make for more workable sill/jamb/head conditions because the frame is either over or outside of where materials stack?
Wood Guy
Apr 13, 16 8:15 pm
curtkram, with thick walls, Euro-style windows, continuous plywood bucks and top-quality tapes and membranes, the location doesn't really matter for installation. Insetting them makes it easier to insulate over the window frames, the weak spot (thermally speaking) in any window. Insetting does require a deeper sill pan but it's not a big deal.
bowling_ball
Apr 13, 16 11:36 pm
We don't insulate over the window frames, unless you're referring to the nailing flange (?). The reason we're seeing this is because when you inset a window even a little, it's surrounded by sheathing or a buck, not insulation. Pushing it outward gets the window inline with the foam and therefore the connection details are closer to the outside of the wall, where our insulation is.
Having said that, yes, it's extremely cold and extremely sunny here. You described it perfectly. I'll try to remember to upload a comparison (by some legit national-level researchers) tomorrow to show you what I'm talking about.
One last point, it's common for us to use 4 or 5 inches of exterior continuous insulation in just about all of our jobs. The details can get tricky when you're hanging cladding out 7" past your structure, without adding significant thermal breaks.
Wood Guy
Apr 14, 16 9:36 am
BB, we don't use flanged windows, we use European Passive House windows. As a rule, they have big frames and can accommodate at least an inch or two of rigid over-insulation.
I used to work at this company and helped develop their details, which you might get a sense of on this page: http://www.ecocor.us/process.php. Ecocor's details are well respected within the PH community; I was heavily involved in getting their system approved as the first certified building component manufacturer outside of Europe. The walls are a true R-58 with no thermal bridging and no foam. Most projects are in the 0.2 to 0.4 ACH50 range. Now that I work on my own I work to all different performance levels, but we used as little foam as possible at Ecocor, and I do the same on my own, preferring other materials whenever possible.
I would be interested in seeing your information, though--one thing I love about this field is that there is always something new to learn!
bowling_ball
Apr 15, 16 2:14 am
Hey I'm sorry I couldn't grab that info today, the last two weeks have been crazy. Taking a half day off tomorrow but in the next few days I'll hopefully be able to share the info I have. Thanks again, I really enjoy discussing these things.
Wood Guy
Apr 16, 16 9:30 am
BB, I might suggest starting a new thread on high performance window, so it has more visibility. There don't seem to be many other energy nerds here but I enjoy discussing better ways to design and build.
go do it
Apr 17, 16 1:01 am
^^ yea you guys keep this conversation going it is very interesting.
Wood Guy can you post a section of your wall assembly? If not foam what do you use?
Non Sequitur
Apr 17, 16 10:32 am
^^ I'm following this too.
Wood Guy
Apr 17, 16 6:59 pm
I can't claim ownership of this wall assembly but I was involved in bringing it from a site-built system to a panelized system. They use a lot of cellulose insulation. Here is an illustration:
2 layers of 3/4" strapping ("furring" outside the northeast US) as a rain screen.
Any siding material, vertical or horizontal (with corresponding changes in strapping orientation).
The 38-perm WRB and oversized rainscreen gap means that the walls can dry easily to the outside. The ZIP OSB sheathing is airtight and vapor-variable, just like the expensive "smart" membranes.
When we used foam it was borate-treated EPS, the most environmentally benign foamed plastic. Since I left they have switched to cork or mineral wool for over-insulating the window and door frames. (By over-insulating I mean covering part of the exposed face of the window or door frame with insulating to improve its performance.)
Cellulose (at least the high-quality, modern version) is an amazing insulation for many reasons. The lowest global warming potential of any insulation, decent R-value, treated with non-toxic borate it's fireproof and essentially pest-proof.
We had to work out unique ways to install cellulose effectively in our large framing cavities, but now that the system is dialed in, they can pretty much fully insulate the house in the shop. Complicated panel connections still have to be insulated on site, but that's just a few framing bays on an entire project.
On some of my own projects I'm fine-tuning a double-stud assembly with cellulose insulation. It's not as perfect as the Ecocor wall but it's also not as thick and it costs less. I'm also doing a project with rigid mineral wool as continuous exterior insulation instead of foam. When I have all the details worked out and field-tested, I can post some section drawings.
Sorry if this is the wrong place on the site to post this, not used to this format of forum interface.
Currently am doing a 1:100 drawing of a building for my final first year project. My exterior walls are 600mm (in line with a low energy insulation standard), and I have a large window size glass pane on one of these exterior walls. This window is flush with the outer surface of the wall.
Does anyone know whether there is a different convention for placement of a window line in the drawing and whether it would be positioned differently, as opposed to just being in 'this' format ===----===?
This is a hand drawing if that helps.
Thank you for any answers provided!
JTAX, I'm not sure what you mean by "window line or what your dashed lines represent. In any section drawing, if you cut through the material, you show it with solid lines, including glass. If the scale is small, show one line for each pane. If the scale is large, show two lines for each pane, preferably with a hatch pattern at the cut through the glass.
If the window (or other object) is in front of or behind the section cut, if it's an important element you can show it with a dashed line. Use different line types or scales for objects in front of or behind the section cut.
Window manufacturers usually show screens as dashed lines.
Are you sure you will be proposing 600mm thick walls (23.4 inches)??
I wouldn't call it "low energy std" by any stretch, since you can pack R-21 ins. value in a 6" thick cav. wall, (exceeding required thermal resistance by most codes)
And no, graphically you may show your window as it sits in reality: closer to the outer wall face (not in the middle of wall). Also don't show window operation on plan. Elevations are better suited for that purpose.
^ my codes have been revised as to required exterior insulation beyond the outer face of studs or sheeting so although a 600mm thick wall is big, it's not ridiculous. Kudos to the OP for using Metric units and not the archaic american ones.
Op, I think a section detail would solve all your plan drafting convention problems.
The Passive Houses I design often have 18" (460cm) thick walls, and we usually place the windows in the center of the wall assembly, as they perform best at that location, though they are usually installed closer to the exterior plane in conventional buildings.
Code minimum is the worst building you can legally build. High performance buildings can save a significant amount of energy, and can be cost effective over the typical length of ownership. They have other benefits as well.
Where to locate the window in the wall plane is an ongoing discussion. Where I work and live, our energy code calls for effective (not nominal) R27 walls. 20" thick walls are common.
Energy modelling has been telling us that the further to the outside of the wall you can go with your window, the better off you are. It used to be all about tying in various membranes, but now even metal pans and flashings are showing up as significant thermal breaks now that our envelopes are so ridiculously tight.
Bowling_ball, I'm curious about your window placement. THERM modeling has been consistently showing us better isotherms with the window closer to the center of the assembly. You must be in a sunny and cold enough location that the additional solar gains of "outies" are worth it?
since your window is part of the moisture/air/vapor system, wouldn't putting towards the outside make for more workable sill/jamb/head conditions because the frame is either over or outside of where materials stack?
curtkram, with thick walls, Euro-style windows, continuous plywood bucks and top-quality tapes and membranes, the location doesn't really matter for installation. Insetting them makes it easier to insulate over the window frames, the weak spot (thermally speaking) in any window. Insetting does require a deeper sill pan but it's not a big deal.
We don't insulate over the window frames, unless you're referring to the nailing flange (?). The reason we're seeing this is because when you inset a window even a little, it's surrounded by sheathing or a buck, not insulation. Pushing it outward gets the window inline with the foam and therefore the connection details are closer to the outside of the wall, where our insulation is. Having said that, yes, it's extremely cold and extremely sunny here. You described it perfectly. I'll try to remember to upload a comparison (by some legit national-level researchers) tomorrow to show you what I'm talking about. One last point, it's common for us to use 4 or 5 inches of exterior continuous insulation in just about all of our jobs. The details can get tricky when you're hanging cladding out 7" past your structure, without adding significant thermal breaks.
BB, we don't use flanged windows, we use European Passive House windows. As a rule, they have big frames and can accommodate at least an inch or two of rigid over-insulation.
I used to work at this company and helped develop their details, which you might get a sense of on this page: http://www.ecocor.us/process.php. Ecocor's details are well respected within the PH community; I was heavily involved in getting their system approved as the first certified building component manufacturer outside of Europe. The walls are a true R-58 with no thermal bridging and no foam. Most projects are in the 0.2 to 0.4 ACH50 range. Now that I work on my own I work to all different performance levels, but we used as little foam as possible at Ecocor, and I do the same on my own, preferring other materials whenever possible.
I would be interested in seeing your information, though--one thing I love about this field is that there is always something new to learn!
Hey I'm sorry I couldn't grab that info today, the last two weeks have been crazy. Taking a half day off tomorrow but in the next few days I'll hopefully be able to share the info I have. Thanks again, I really enjoy discussing these things.
BB, I might suggest starting a new thread on high performance window, so it has more visibility. There don't seem to be many other energy nerds here but I enjoy discussing better ways to design and build.
^^ yea you guys keep this conversation going it is very interesting.
Wood Guy can you post a section of your wall assembly? If not foam what do you use?
^^ I'm following this too.
I can't claim ownership of this wall assembly but I was involved in bringing it from a site-built system to a panelized system. They use a lot of cellulose insulation. Here is an illustration:
http://www.ecocor.us/wall-systems.php.
From the inside out:
The 38-perm WRB and oversized rainscreen gap means that the walls can dry easily to the outside. The ZIP OSB sheathing is airtight and vapor-variable, just like the expensive "smart" membranes.
When we used foam it was borate-treated EPS, the most environmentally benign foamed plastic. Since I left they have switched to cork or mineral wool for over-insulating the window and door frames. (By over-insulating I mean covering part of the exposed face of the window or door frame with insulating to improve its performance.)
Cellulose (at least the high-quality, modern version) is an amazing insulation for many reasons. The lowest global warming potential of any insulation, decent R-value, treated with non-toxic borate it's fireproof and essentially pest-proof.
We had to work out unique ways to install cellulose effectively in our large framing cavities, but now that the system is dialed in, they can pretty much fully insulate the house in the shop. Complicated panel connections still have to be insulated on site, but that's just a few framing bays on an entire project.
On some of my own projects I'm fine-tuning a double-stud assembly with cellulose insulation. It's not as perfect as the Ecocor wall but it's also not as thick and it costs less. I'm also doing a project with rigid mineral wool as continuous exterior insulation instead of foam. When I have all the details worked out and field-tested, I can post some section drawings.