When excavation began on June 9th, 2010 a rainbow filled the eastern sky. It would have been fitting to see Porter and Sons Construction singing "Somewhere Over the Rainbow" and clicking red sequenced work boots while saying "There's No Place Like Home". But this is Walla Walla, Washington, not Tornado Alley Kansas, and I suspect neither Mark nor Ben Porter can carry a tune like Judy Garland or own red sequenced construction boots for that matter! ;) Okay everyone, this was my attempt to make a witty remark on my first construction post. If you have been following the blog existingresources.wordpress.com/ documenting the construction of the first Passive House being built in Seattle, WA you will notice that Linda always creates a witty post title and commentary followed by a more serious discussion of what's happening in the construction process, so I thought I'd borrow from her. Sorry Linda, if this is a literairy infringment on your creative talent! Feel free to comment folks that I should keep the project stuff and not poor attempts at being funny!
The property is a 5-acre parcel with unobstructed solar resources to the south, the lot slopes gently to the north with views of the Blue Mountains to the east. A major design consideration was to take advantage of the sun for daylighting and for winter time passive solar gain through south facing windows. Passive solar design strategies add no cost and take advantage of a free, clean, and sustainable energy source. The sun has been coming up every morning for a long time and will continue to do so long after we are all gone so take advantage of the sun's path in your next project. A home that is elongated east to west and oriented to true south has the optimal solar benefit. As you can see in Figure 1, our house is oriented about 10 degrees east of true south. As general rule, if your home stays within 20 degrees east or west of true south it will receive about 92% of the solar benefit. We were willing to sacrifice a little on the optimum south orientation in order to gain early morning light and to provide better mountain views to the east.
Figure 1. Site Plan
Here are some very general rules of thumb for passive solar design. Be on the look out for future posts that provide a more indepth discussion of each of these strategies!
1) Orient your home to face south
2) Utilize south-facing windows and glass doors to collect solar energy
3) Locate the main living areas on the south side of the floor plan
4) Provide for exposed thermal mass to store heat for use when the sun is not out
5) Provide for natural convection and circulation through open architecture and operable windows and vents
6) Locate non-living area on the north side and minimize north side building exposure
7) Provide for a superinsulated and airtight building envelope, while providing whole house energy recovery ventilation
8) Provide for adequate shading of south windows for summer cooling
