The Lay of the Land...and the Layout!
In the first part of the project, the lot grading plan, the foot print of the house and the layout are all planned together to ensure that the internal layout of the building matches the best orientation on the lot to capture solar gains. Solar gains change very little over 15 degrees east or west of the south direction, so changing the orientation by that amount have a huge effect. The picture below shows 4 possible orientations based on the lot grading plan.
The lot is a bit of an odd shape but the back yard has an orientation facing within 15 degrees of south. The dark dashed line with the arrows is a line of constant height in front of which we would wish to keep the house foot print mainly because beyond this line, the land slopes about 50 cm per contour line, Its a gentle slope but will require more clearing and more fill. The south west of the lot is basically a field and will require little clearing. It seemed like the best place for a septic. Pushing the house as far to the west on the lot as possible seemed like a natural choice given the natural grades and the septic position. The footprint of the house will need to be at least 15' away from the survey line so I may not be able to leave many trees on my lot but the neighbour in the next lot has left a buffer of about 15' on his side with no plans for taking down any more. Since we have already decided that we like two out of the four schematics, we are not considering the bottom two layouts on the site schematic.
Here are the two layouts we are evaluating:
Both plans are about 2000 sf. From an energy perspective, I think that sch-1 is a better plan. All the living areas on both levels are on the south side of the house. As long as the eave overhangs are large enough and there is some sort of trellis over the windows on the main level, summer time over heating will not be an issue and the rooms will always be bright. In sch-2, the designer (Mike Anderson) has surmised that the roofline may be very high in order to accommodate the rooms upstairs and thinks it may look very tall from the road on the account that the attic will contain almost 30" of insulation so the heel trusses will extend the height of the walls above any windows by at least 2'-3'. Another option could be a 1 1/2 story for sch-2. In which case none of the bedrooms would have any south facing windows. At this point nobody really knows and we'll get a better perspective once some 3D modeling is completed.
So the next round of schematic will involve melding sch-1 and sch-2 in order to get the best of both plans. You can see that house is not huge by any means. Its about the same size as our current house minus the basement. Basements can be a great space...but they suck energy big time. My plan is to use attic trusses over the garage and use that space to replace the storage that we have now in our under-utilized, energy inefficient basement.