Hello!

I was very excited to find this forum. I will be building in the fall and we are finalizing the plans and trying to come up with a good site plan at this point.

As it stands, the bulk of our windows are at 45 degree south east.  The house would look nicer if the windows would face even more east (60 degrees or so)but I'm trying as much as I can to align them south. It's also important to note that I live in a heavily wooded area but I am planning on situating the Septic bed south of the house so more sun can get through. (Edit: Location of the lot is near Ottawa, Ontario. 45° 19' N  75° 40' W)

HOWEVER, my research seems to conclude that anything more than 30 degrees off pure south isn't very effective since the light is reflected off the windows.

I'd like your opinion on what I should do:

a) Since it's not that effective at 45 degree south-east, just go for the look and move it even more east . If that is the case, are there any special types of windows (east-facing) I should be putting in?

b) 45 degree angle is better than nothing so leave it at 45 degree South East like in the drawing. Again, any special considerations for windows at this angle?

c) Any other suggestions??

Here is the picture of my property and the house/garage on it at a 45 degree angle. Please note the garage and house are attached but to simplify things I drew them separate.

http://picasaweb.google.com/lh/photo/uNqCxDTxnXZ5YW92TPV_0A?feat=directlink

Thanks in advance!

Stephanie

The answers to a lot of questions on this forum are site specific.  I believe Ruissellet Rd is in Ontario near Ottawa.  Maybe someone on this forum can now answer your questions.

Yep, it is indeed near Ottawa, Ontario. Thanks I should have put that extra info on there.

Conventional wisdom is to orient passive solar homes within 10 degrees of south ... so at 45 degrees off you obviously can't expect to get optimum performance. It isn't clear to me from the picture of your site why your proposed house can't be turned more north-south, but assuming it can't there is probably some combination of window and glass type (and shading for summer sun) that will give you maximum overall performance (meaning for your location/orientation/shading, etc).

There may be benefit to greater rotation and optimizing the windows on the former south-west side (now ~south) for maximum solar gain (perhaps using increased thermal mass in that area to trap as much of the heat as possible .... ?). It's sub-optimal, but every bit helps. You may also want to consider reducing the area of now east facing glass on the long side of the house (and/or using low heat gain glass on that side) to increase summer comfort.

Note that increasingly advice is to choose the windows to match the orientation of each side of the house. Also note that north facing windows can benefit from reflected solar and, overall, with the use of high solar gain glass in high performance designs can have positive ER ratings (i.e. gain more heat than they lose over the year). The demands of South, East, West and North vary over the day and over the seasons of the year and there is a preferred window/glass type for each.

Working out the optimum for your design is way beyond me, but you are close to one of the premiere window manufacturers in North America (Thermotech Fiberglass, on Antares Drive in Ottawa http://www.thermotechfiberglass.com/index.htm), so I'd suggest consulting with them. They can probably help or point you toward someone who can.

Thanks for the quick reply agb90spruce!

I contacted thermotech via their website as you suggested. Thanks for the head up.

It's a tough call. I'm still not sure what to do.

- The shorter south-west side is a bedroom so putting in a lot of windows there is probably not a good idea. (maybe I'm wrong?)
- I guess what I'm unclear on is if we'd be better off having the rear windows face east and put appropriate east facing windows to maximize gain OR rotating the house south-east and then coming up with windows what would be optimal there. I think that's where the window companies might be able to help.
- We would love to keep the gorgeous rear view we have to the back of the property from the living room. Rotating the house to anything more than 45 degrees would mean the view would become our neighbour's house.

I think that considering the heavily shaded property, what we have to concern ourselves with is more keeping our generated heat in using thought out insulation layers and minimizing thermal bridging/ heat loss through windows and doors.

A little aside: If you look at my link again you will see that the garage has the long side facing south. I was thinking that would be an excellent place for solar panels (or over the septic tank) when they become more cost effective :)

Again, thanks for the advice and if anybody else has suggestions bring them on!

I agree lot's of windows in a bedroom won't do it.

I can relate to your concerns. My wife and I are planning a, ~2500 sq ft house on a lakefront lot with a north view of the lake, lots of mature trees, a neighbour to the west and a gradual hill rising to the south. Suffice to say its a problematic lot to build on if one wants an energy efficient passive solar house that minimizes views of the neighbours while maximizing the views of the lake and a rocky ridge to the east. That said, we are able to site the house so the major axis runs east-west, so out issue is mainly reconciling the view with the north exposure. Our thinking re windows (subject to budgetary reality!) is to plan on thermal gain from suitably shaded southern windows and to use mainly non-opening, high solar gain, triple pane fiberglass windows on the north side. We are still defining the best mix of windows but are confident we can come up with a plan that will work.

Our approach is similar to yours ... a highly insulated envelope (SIP construction with ~R-40 walls and R-60 roof). The advantage of SIPs is the almost total lack of thermal bridging and the relative ease of obtaining an airtight building. We, like you, are planning a garage with the long side facing south and a 45 degree slope roof to allow for future solar. We have chosen to site the garage to as much as is practical block views of the neighbour without blocking the view of the lake across his front yard. Would that be practical or you? If so, you could maximize your "gorgeous rear view", have a southern exposure on the front toward your neighbours, but blocking actually seeing them using the garage. Alternatively do you have any freedom to juggle where the various rooms are? Sometimes some brainstorming can help.

Anyway, good luck with it. .... Andy

The link I posted in my original question shows the garage and house as being seperate but they are actually attached by a mudroom, half bath and a laundry room.We tried changing the plan around to make it more efficient but we want a bedroom on the first level and having the kitchen/dining/mudroom near the garage makes more sense than the bedroom so I think the plan will likely remain as is. Also, we like that the garage is currently on the north side of the house and blocks the cold winds. (Also, no windows needed on the garage so no north facing windows! )

Let's hope the window supplier can shed the light on the south-east vs east dilemma.

Good luck with your project as well, sounds like a great location for a house, even though it's a bit challenging for passive solar.

Hi! I found a great article that compares superwindows to glazings relating to direction:

http://gaia.lbl.gov/btech/papers/37130.pdf

Why can't you just orient the long axis south?   You have a fully wooded lot, clear it apropriately for solar gain and privacy.  Bring the driveway in along the south side.  Slide the house a bit to the north on the lot.  Clear alot to the south and not so much to the east, west and north.  You should still be abe to get privacy and good solar gain. 

Make sure you are using solar south, not magnetic south in your calculations.

Cheers,
Eric

Thanks for posting this link! I find it to be most informative. As I plan our future house, I will consider some of the findings in the report, such as the importance of SHGC in window selection.