21 squares is approximately 195 sqm. As stated, build as close to the side boundaries as possible. Which, depending on where you are, should be around 17m. For 195sqm, this will give you a depth of 11.5m.
17m x 11.5m isn't bad at all. Stretching the house out is great for solar access & cross-ventilation. But for cooler climates you actually don't want to stretch out the house too much, as this increases the exterior surface area, which are areas of heat loss. Taking this to an extreme, many European passive haus's are boxy 2 storey building, which have a low exterior surface area / internal volume ratio.
But for here, I think a 17m x 11.5m is great. If you go a U shape, you'll be increasing your exterior surface area to internal volume ratio, resulting in increased areas of heat loss. This increased exterior surface area will also require more material to build & result in higher building costs.
As stated previously, living areas out the back facing N. Majority of glazing facing this direction. But don't go overboard, as windows are poor insulators (even true for DG units, when compared to other materials). Appropriate N facing eaves to admit winter sunlight, while blocking summer sun. Thermal mass in north facing living areas, which will capture & store heat from that winter sunlight, releasing it at night. Ie. It will smooth out the peaks of daytime maximums & nighttime minimums. A dark coloured, insulated, polished or tiled concrete floor is a good option.
If possible, no W facing windows, large eaves. Also service areas to this area, garage, bath rooms, laundry.
E, similar to W, though you can get away with some minimal glazing. A good place for veranda/covered alfresco area. As it will be well shaded, but will admit some light.
S, bedrooms. As these can generally be in cooler areas of the house. Some glazing for cross-ventilation of summer breezes.
These can be used as a guide, they're not hard & fast rules. A lot will depend on the layout of your block. Eg. You may not want bedrooms at the front of the house, if you live on a busy road, or if a lot of time will be spent in them during the day (think kids rooms), as they'll be colder areas of the house.
Clerestory windows may be a good option to admit light, but be very careful with heat loss. The warmest air in your house will be up near your ceiling, & you don't want this escaping. So don't go overboard & definitely use good DG units with high R values. I'd actually go N facing clerestories, with appropriate eaves for summer shading. Depends if you want direct winter sunlight to the middle of your house though. Think faded furniture, direct light in the eyes etc. If you do go for N facing clerestories you could have an additional thermal mass wall in the interior, that is hit by this direct sunlight. S facing clerestories could leak a fair bit of heat in winter. Also, the sun's path only travels to the S in summer, meaning that at that time of year there's an additional area of heat gain. That may not be quite as critical an issue in your climate as in other climates.
I'm definitely no expert, just my views after lurking here & elsewhere for some time.
Posted Friday 15 Nov 2013 @ 2:35:13 pm from IP
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