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Green Principles
Basic Principles of Green Design
Angus W. Macdonald has been designing green buildings before the terminology became popular. He has provided Survival Consultants plan sets to owner builders in almost every state, many of which are truly fossil fuel independent. He wrote the book, Building Your Own Earth Tempered Home: a Construction Manual; he coined the phrase “EarthTempered” to acknowledge the debt we owe to the thermal inertia and conductivity of the earth’s crust in our quest for energy independent housing. Earth tempering is as important as passive solar gain and insulation in creating architecture that requires no fossil fuel input to maintain year-round comfort in temperate zones. Manipulation of this trio, earth tempering, solar aperture and storage, and isolation from exterior temperature variation, is the fundamental principle of true green design. Survival Consultants' proven passive solar and earth tempered plans are now incorporated into this website, and am-cor unified steel & cement systems structural SHELL & PANEL PAKS are now available for them.

Principles Of Green Design

Land Planning

inner city infill elevation watercolor
new fireproof, mold, vermin, bacteria, fungus & mildew resistant insulated construction inside existing masonry townhouse shells use existing infrastructure but conserve energy

America has been planned for automobile addiction. One of the greenest things you can do is to site your home for accessibility to shopping, transportation, and work. Some of the greenest sites from this standpoint are in blighted urban areas. Existing urban infrastructure for transportation and utilities poses no additional environmental impact. Unoccupied waterfront industrial sites often offer dramatic reuse opportunity. Reuse of existing building shells requires much less energy than new construction.

green rehab industrial section
Super insulated modules placed inside existing industrial shell, original fenestration removed, balconies between modules and exterior wall, interior multi-level street, shared solar heating & power.
green rehab industrial view
walled garden, living modules, balconies, existing masonry shell, shared solar

green rehab residential section
Super insulated modules placed inside gutted masonry shell, original fenestration removed, balconies between modules and exterior wall, solar heating & power.
green rehab residential view
walled garden, living modules, balconies

Orientation & Situation

Weigh relative importance of practical location with preferred view and aspect.
Choice of location on site:
  • identify location of maximum solar aperature (hours of winter sunlight)
  • with minimum clearing requirement
  • ease of canopy replacement

  • south facing slope in Northern Hemisphere

  • locate near crest for minimum site drainage requirement
  • not in a swale

  • access to power, water, and waste disposal, based on degree of energy independence
  • on or off power grid
  • public water supply, well, or rainwater catchment
  • sewer, drainfield, or compost disposal system

Energy Constants

Solar Heating: In temperate zones, depending on latitude, the Sun provides the most energy during Winter at an average of 20º to 30º from horizon. During Summer, depending on latitude, the angle is much greater. This energy is more than sufficient to provide electrical power, heating for interior spaces, and domestic hot water.

Adding a trellis to the south front of a passive solar design mitigates summertime heat without interfering with wintertime solar gain.
sun cape patio perspective sketch
south facing patio to a solar home

An intermediate floor acts as a thermal diaphragm for both solar heated water and passive wintertime gain.
sun cape solar section diagram
composite section of passive & active systems

Solar Cooling: Passive solar cooling uses prevailing winds to bring earth cooled air into living areas. Passive solar gain is used to heat solar chimney vent surfaces, drawing hot air up and out of the house. Hybrid cooling uses coolth tubes run through foundations to cool and recirculate interior air with photovoltaic powered fans.

5_a solar cooling section diagram
solar cooling by convection
5_b coolth tube section diagram
active earth tempering by using underground pipes to cool air, which is distributed by a solar powered fan

1_a earth tempered diagram
crust conducts constant energy from 8’-12’ below surface

Geothermal: In temperate zones, from 8 to 12 feet below surface, the earth’s crust maintains a steady temperature from about 63ºF during Summer to about 67ºF during Winter depending on latitude, exposure, soil type, and location. The thermal inertia of the crust retains higher Summertime temperature late into the Winter season, and conversely, lower temperature late into the Summer season. This “flywheel” effect of the crust makes it an ideal heatsink for solar heated and earth-cooled homes. The small difference between the temperature conducted into an earth sheltered dwelling and desired interior range of about 70ºF (from some 3ºF to 8ºF) is easily met by passive solar heating during Winter.

sun cape entrance perspective watecolor
Solar atriums, greenhouses, and sun rooms are effective passive solar gain elements which also form attractive living spaces.

Design Geometry

Passive solar design means formation and placement of structural elements of a building so as to:
  • gather solar energy
  • retain and store solar energy
  • distribute solar energy throughout the building
  • isolate living spaces from exterior temperature variation.

Because the building itself is formed to provide both energy and accommodation without excessive mechanical equipment, passive design offers the least expensive and most reliable form of green architecture. Such building elements can be sculptural and beautiful in fulfilling their energy and structural requirements.

Passive solar design elements include:
2_b trombe wall convective diagram
thermocouple: indirect passive solar gain & distribution by convection
5_b coolth tube section diagram
direct passive solar gain: distribution by radiation and conduction

3_a sun cottage section diagram
photovoltaic array & trombe wall windowsill

Earth Tempered & Solar Receptive

Passive solar design can be made truly responsive to the environment when coupled with earth tempering, insulation, protection from summertime sunlight, and a combination of radiant, conductive, and convective solar energy elements.

Solar City Planning

Solar energy based community design incorporates humanistic and historic zoning for mixed-use rather than exclusive-use zones, reducing not only the distance from dwelling to shopping and from dwelling to work, and consequently the need for automobile use, while enlivening neighborhoods by incorporating recreation, entertainment, commercial uses along with residential. Outdoor gardens and both passive and active solar power, hot water, and space heating generation are possible through responsive design.

Material Choice

Lifecycle analysis looks at the energy requirement and environmental impact of extraction, manufacture, and transportation of building materials, as well as their durability. Rebuilding and repair of buildings is a major economic factor and has great impact on both environment and energy consumption. Choose materials that are:
  • long lasting for minimal replacement cost
  • have low maintenance requirement and cost
  • are energy conservative (insulative and/or high thermal inertia)

These factors will in the end outweigh initial energy requirement to manufacture and transport to site, because building life is (or should be) so long, and the energy required for heating and cooling is so great for a poorly designed building. 80% of fossil fuel consumption in USA is used for heating and cooling.

For instance, plastics, and plastic based stuccos (Petroleum product derivatives) are poor choices for exterior use because they deteriorate in UV light (sunlight). Wood products are a poor choice for sealed-cavity structural use because they are subject to vermin, termites, ants, mold, mildew, bacteria and fungus. Green, durable, and sustainable material choices for exterior use would be inert, long-lasting, sun and water resistant materials such as: ceramic (tile or brick), concrete, Portland cement based stucco (such as amcorite), glass, and stone. Green material choices for sealed cavity structural use would be reinforced concrete, galvanized (rust-proofed) steel, or structural clay tile. Insulation should be inert, free from contribution to flame or out-gassing for fire safety, and free from Urea-Formaldehyde (UF) for indoor environmental quality.

Green designs should be planned and engineered for disaster resistance so as to avoid human tragedy, as well as replacement cost and its environmental impact. Macdonald Architecture & Technology has a number of plans designed with these aspects in mind, such as the New Providence, the Winchester, the Creole Cottage, and the Tropic Series.
Modified 2006-06-04