Conceptual Basis of Planning and Building

There is a rapid evolution occurring in planning for sustainability in general and solar buildings in particular, brought about partly by the climate crisis. This evolution affects six aspects of planning and architecture which are, to the extent applicable, incorporated into Blacktail Solar Homes.

  1. Combination of passive with photovoltaic design rather than being conceived as separate elements
    Merger of passive heating and cooling with increasingly inexpensive photovoltaic panels.
  2. Thin vs thick buildings
    Moving to achieve the two distinct advantages of thinner buildings: (a) allowing greater penetration of winter daylight for passive heating; (b) reduction of shading adjacent buildings.
  3. Natural daylighting
    Daylighting, an essential component of an energy conserving, healthy building is emphasized.
  4. Thermal mass application
    Recent developments in supplying thermal mass have the potential to break this bottleneck in applying economical passive heating and cooling for climates like Dillon.
  5. Storm water as a resource
    Storm water, traditionally conceived as a big expense pushed to the public realm, can through Low Impact Development techniques become an asset to Montana's water resource.
  6. Auto-centric vs social-centric
    Automobile dominant planning is being replaced by transportation planning that provides choice and diversity.

Passive Design Basics

A tongue in cheek description of sound passive solar design can be found at The 4 Donkey Method of BioClimatic Design
... or how to build a passive solar home, and do it really green!
by Ron Swenson

The four basic elements discussed in The 4 Donkey Method of BioClimatic Design are as follows:

  • Orient the structure with the wide side facing the sun. Summer shade is just as important as winter sun. Then specify the right kind of glass windows to allow the sun to heat the house in winter. Specify a different type of glass for windows that would overheat the building in summer.
  • Use the principle that hot air rises to distribute the heated air (in winter) or cooled air (in summer) to provide comfort throughout the house.
  • Include sufficient mass to absorb some of the heat during the winter day for later use when the sun is gone. In summer the mass will absorb some of the excess heat.
  • Use insulation to capture and hold available heat in winter, and exclude excess heat in summer. To be most effective, insulation must be on the outside of the mass being insulated.

Learned books have been written about each of these four simple elements, with many variations of how to accomplish each of them. Although no building project can embrace all of these good ideas, Blacktail Solar Homes use these techniques to the greatest extent possible while still keeping them affordable.