Green Design:

As indicated in the conclusion of part 1 of this article, green design uses green strategies to attain a project that is more energy and water efficient and provides a healthy environment for the occupants. The next part of this article will concern sustainable design.

As discussed in Part 1, sustainable design must provide a project that is able to maintain itself (conserving an ecological balance by avoiding depletion of natural resources).

In order to maintain itself the final project would have to be carbon neutral, net zero energy use, net zero water use and maintain a comfortable and healthy environment.

Net zero energy use would mean that the designed project would have to generate all of the project’s energy requirements on site. This could be attained by using solar energy, wind energy, hydro energy or geothermal energy. In order to mitigate the high initial cost of these methods of onsite energy generation, project and occupant energy use should be lowered by using green strategies that lower energy use. Some of these strategies include the following:
  • Day lighting to lower artificial lighting use.
  • Well sealed and insulated building envelope to lower heating and air conditioning requirements.
  • Use natural ventilation.
  • Use higher reflectance materials on the exterior to prevent absorption of solar energy and heating interior spaces.
  • Provide buffers such as vestibules between the exterior and interior spaces at access locations.
  • Provide landscape shading of the building.
  • Provide operable shutters, window shading that prevent direct sunlight entering the building but allow daylight and views during months that require interior cooling.
  • Use thermal mass to slow the movement of exterior extreme temperatures to the interior.
  • Use solar energy for heating in the cold months of the year (trombe wall).
  • Use of solar heating for hot water.
Net zero water use is more difficult to attain. In order to attain net zero water use, the project must recycle and collect water. Water use should be minimized by using strategies that lower the amount of water used. Many of these strategies will require life cycle changes by occupants. Some water use strategies may include the following:
  • Use of low flow faucets and shower heads.
  • Use of water closets that use less water to flush or better yet the use of composting toilets.
  • Recycle all water including gray and black water by using an onsite constructed wetlands or living machine.
  • Provide a water filtering process that allows recycled water to be sterilized for human consumption.
  • Collect rainwater and storm water from the site to replace water lost to evaporation in the recycling process.
  • Take shorter showers less often.
  • Use hydroponics for food growth as it uses 90 to 95 percent less water than gardens.
These and other water strategies could cut water use to that being naturally collected.
Finally, a sustainable design should provide a comfortable and safe environment for its occupants. This can be attained by using products that do not contain chemicals that are harmful and cause health problems. Some of these harmful chemicals include:
  • Volatile organic compounds
  • Perfluorinated compounds
  • Flame retardants
  • Phthalate plasticizers
  • Isocyanate-base polyurethane
  • Urea-formaldehyde
  • Carbon monoxide
No product that contains these chemicals should be used in a sustainable design.
In order for the design to be comfortable for the occupants the interior environment must provide comfortable levels of ventilation, temperature and humidity.

Now that I am at the end of Part 2, have you noted that I have not said a word about being carbon neutral. I have decided that a sustainable design would not necessarily need to be carbon neutral but a regenerative design would. We will get into that in Part 3.

Originally from Canada, John Lansdell is a true architectural technologist with over 40 years of experience in the design and construction industry. John joined LGA in 2006 to fulfill his desire to work on specific projects of high integrity and sustainability and has since received his Master of Science in Green Building at the San Francisco Institute of Architecture.