According to the California Energy Commission and all empirical evidence gathered to date, the proper orientation of a building is north-south.  This more practically means that the long axis of a structure should be oriented east-west with the majority of windows and livable spaces along the north and south facades.  This notion has been co-opted by homebuilders and used as a marketing tool for homes that line their east-west oriented street grid.  Unfortunately, this is slightly misleading.

In the early housing boom in the 1910’s and 20’s, homes were built with using sound principles of passive solar design.  Neighborhoods such as Willo, Encanto and Arcadia here in the Phoenix area were developed with lots that were longer than they were wide, just as they are today.  Willo lots measure approximately 70’ by 120’ where as Arcadia lots measure approximately 130’ by 180’.  This accommodates the homebuyers desire to have a back yard capable of becoming a private resort.  Homes are generally built along the east-west axis, windows and livable spaces along the north and south facades.

In the 1940’s and 50’s homebuilders were challenged to be more efficient with the land and provide more density.  This was accomplished by shortening the lot, becoming more square and maintaining the north-south orientation of the homes.  In the adjacent photo of post war Scottsdale, lots have been reduced to approximately 70’ by 100’.  Only the backyards have been compromised to accomodate this change.

Now we fast forward to the latest housing boom here in the Valley of the 1980’s through 2000’s.  The critical change that occurred during this period was less about increased efficiency and more about decreased costs.  Lots were reduced to a typical width inorder to decrease the infrastructure cost for each lot, that is, reducing the amount of street frontage per lot to about 50’.  This change was a winner for the bottom line of builders, however this required a rotation of the homes orientation to east-west due to the narrow constraints of the property.  In order to maintain the illusion of “north-south” orientation builders provided homebuyers with either a windowed northern or southern façade.  This is hardly the intent of passive solar design.

I hope that the next step in suburban home evolution will be a return to proper orientation or to rethink housing products all together.  Have you seen a good example in your city that addresses passive solar design and the economics of tract home building?  Please let me know, I look forward to a good discussion!